<PAGE>   1
                                                                    EXHIBIT 10.5


         NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON
         CONVERSION HEREOF HAVE BEEN REGISTERED WITH THE UNITED STATES
         SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES
         COMMISSION OF ANY STATE OR UNDER THE SECURITIES ACT OF 1933,
         AS AMENDED. THE SECURITIES ARE RESTRICTED AND MAY NOT BE
         OFFERED, RESOLD, PLEDGED OR TRANSFERRED EXCEPT AS PERMITTED
         UNDER THE ACT PURSUANT TO REGISTRATION OR EXEMPTION OR SAFE
         HARBOR THEREFROM.

No. 00- 3                                                      US $ 2,800,000.00
    -----                                                         --------------

                                  CORZON, INC.
                                formerly known as
                         TANNER'S RESTAURANT GROUP, INC.

              8% AMENDED AND RESTATED SECURED CONVERTIBLE DEBENTURE
                              DUE JANUARY 25, 2003

        THIS DEBENTURE, as amended and restated, is one of a duly authorized
issue of up to $4,553,652 in Debentures of CORZON, INC., formerly known as
TANNER'S RESTAURANT GROUP, INC., a Texas corporation (the "Company") designated
as its 8% Secured Convertible Debentures. Such Debentures may be issued in
series, each of which may have a different maturity date, but which otherwise
have substantially similar terms. Capitalized terms not otherwise defined herein
shall have the meanings ascribed to them in the Securities Purchase Agreement,
dated June 7, 2000 (the "Securities Purchase Agreement"), by and among the
Company and the Buyers (as that term is defined therein).

         FOR VALUE RECEIVED, the Company promises to pay to SHERMAN LLC, the
registered holder hereof (the "Holder"), the principal sum of Two Million Eight
Hundred Thousand Dollars and No Cents (US $2,800,000.00) on January 25, 2003
(the "Maturity Date"), and to pay interest on the principal sum outstanding from
time to time in arrears (i) prior to the Maturity Date, semi-annually, on the
last day of June and December of each year beginning on December 31, 2001, (ii)
upon conversion as provided herein or (iii) on the Maturity Date, at the rate of
Eight Percent (8%) per annum accruing from January 25, 2001(the "Issue Date").
Accrual of interest shall commence on the first such business day to occur after
January 25, 2001, and shall continue to accrue on a daily basis until payment in
full of the principal sum has been made or duly provided for.

         This Debenture is subject to the following additional provisions:

         1. The Debentures are issuable in denominations of Ten Thousand Dollars
(US$10,000) and integral multiples thereof. The Debentures are exchangeable for
an equal aggregate principal amount of Debentures of different authorized
denominations, as requested by


<PAGE>   2


the Holder surrendering the same. No service charge will be made for such
registration or transfer or exchange.

         2. The Company shall be entitled to withhold from all payments of
principal of, and interest on, this Debenture any amounts required to be
withheld under the applicable provisions of the United States income tax laws or
other applicable laws at the time of such payments, and Holder shall execute and
deliver all required documentation in connection therewith. The indebtedness
evidenced hereby is subject to set-off in accordance with the provisions of that
certain Agreement and Plan of Merger among LecStar Communications Corporation, a
Delaware corporation, the Company and a wholly-owned subsidiary of the Company
dated January 5, 2001.

         3. This Debenture has been issued subject to investment representations
of the original purchaser hereof and may be transferred or exchanged only in
compliance with the Securities Act of 1933, as amended (the "Act"), and other
applicable state and foreign securities laws. In the event of any proposed
transfer of this Debenture, the Company may require, prior to issuance of a new
Debenture in the name of such other person, that it receive reasonable transfer
documentation, including legal opinions of counsel reasonably satisfactory to
the Company, that the transfer of the Debenture to such other persons does not
and will not cause a violation of the Act or any applicable state or foreign
securities laws. Prior to due presentment for transfer of this Debenture, the
Company and any agent of the Company may treat the person in whose name this
Debenture is duly registered on the Company's Debenture Register as the owner
hereof for the purpose of receiving payment as herein provided and for all other
purposes, whether or not this Debenture be overdue, and neither the Company nor
any such agent shall be affected by notice to the contrary.

         4. A. The Holder of this Debenture is entitled, at its option, subject
to the following provisions of this Section 4, to convert all or a portion of
this Debenture into shares of Common Stock of the Company, $.01 par value per
share ("Common Stock") of the Company at any time beginning one year from the
Issue Date and ending on the Maturity Date, at a conversion price for each share
of Common Stock (the "Conversion Price") equal to the lower of (x) $0.75 per
share (which amount is subject to adjustment as hereinafter provided; the "Fixed
Conversion Price"), or (y) the Variable Conversion Price (as defined below).

            B. For purposes of this Debenture, the following terms have the
meanings indicated below:

            (i) "Market Price of the Common Stock" means the closing bid price
of the Common Stock for the period indicated in the relevant provision, as
reported by Bloomberg, LP or, if not so reported, as reported on the
over-the-counter market.

            (ii) "Variable Conversion Price" means (x) seventy-five percent
(75%) of (y) the average of the five (5) lowest Market Price of the Common Stock
during the twenty (20) trading days immediately preceding the relevant
Conversion Date (as defined below), except


                                       2
<PAGE>   3


that, to the extent any such trading day occurs prior to the effectuation of a
stock split or similar transaction occurring after the date hereof and on or
prior to the relevant Conversion Date, the Market Price of the Common Stock used
in determining the Variable Conversion Price will be equitably adjusted to
reflect such transaction.

                  C. Conversion shall be effectuated by faxing a Notice of
Conversion (as defined below) to the Company as provided in this paragraph. The
Notice of Conversion shall be executed by the Holder of this Debenture and shall
evidence such Holder's intention to convert this Debenture or a specified
portion hereof in the form annexed hereto as Exhibit A. Interest accrued or
accruing from the date of issuance to the date of conversion or to the Maturity
Date, as the case may be, shall be paid, at the option of the Company, in cash
or, subject to the provisions of Section 4(D) hereof, in Common Stock at the
Conversion Price then applicable as of the Conversion Date. No fractional shares
of Common Stock or scrip representing fractions of shares will be issued on
conversion, but the number of shares issuable shall be rounded to the nearest
whole share. The date on which notice of conversion is given (the "Conversion
Date") shall be deemed to be the date on which the Holder faxes or otherwise
delivers the conversion notice ("Notice of Conversion") to the Company so that
it is received by the Company on or before such specified date, provided that,
if such conversion would convert the entire remaining principal of this
Debenture, the Holder shall deliver to the Company the original Debenture being
converted no later than five (5) business days thereafter. Facsimile delivery of
the Notice of Conversion shall be accepted by the Company at facsimile number
(203) 335-1455; Attn: Larry Shatsoff, President. Certificates representing
Common Stock upon conversion will be delivered to the Holder at the address
specified in the Notice of Conversion (which may be the Buyer's address for
notices as contemplated by the Securities Purchase Agreement or a different
address), via express courier, by electronic transfer or otherwise, within three
(3) business days (such third business day, the "Delivery Date") after the date
on which the Notice of Conversion is delivered to the Company as contemplated in
this Section 4(C).

                  D. Notwithstanding any other provision hereof or of any of the
other Transaction Agreements, in no event (except (i) with respect to a
Redemption Notice Conversion (as defined below), (ii) as specifically provided
in this Debenture as an exception to this provision, or (iii) while there is
outstanding a tender offer for any or all of the shares of the Company's Common
Stock) shall the Holder be entitled to convert any Debenture or shall the
Company have the obligation to convert all or any portion of this Debenture (and
the Company shall not have the right to pay interest on this Debenture) to the
extent that, after such conversion, the sum of (1) the number of shares of
Common Stock beneficially owned by the Holder and its affiliates (other than
shares of Common Stock which may be deemed beneficially owned through the
ownership of the unconverted portion of the Debentures), and (2) the number of
shares of Common Stock issuable upon the conversion of the Debentures with
respect to which the determination of this proviso is being made, would result
in beneficial ownership by the Holder and its affiliates of more than 4.99% of
the outstanding shares of Common Stock (after taking into account the shares to
be issued to the Holder upon such conversion). For purposes of the proviso to
the immediately preceding sentence, beneficial ownership shall be determined in
accordance with Section 13(d) of the Securities Exchange Act of 1934, as


                                       3
<PAGE>   4


amended (the "1934 Act"), except as otherwise provided in clause (1) of such
sentence. The Holder, by its acceptance of this Debenture, further agrees that
if the Holder transfers or assigns any of the Debentures to a party who or which
would not be considered such an affiliate, such assignment shall be made subject
to the transferee's or assignee's specific agreement to be bound by the
provisions of this Section 4(D) as if such transferee or assignee were the
original Holder hereof.

            E. Anything herein to the contrary notwithstanding, in the event the
Company breaches the provisions of Section 4(g) of the Securities Purchase
Agreement, the Conversion Price shall be amended to be equal to (i) 90% of (ii)
the Conversion Price determined in accordance with the other provisions of this
Debenture without regard to this Section 4(E), and the Holder may require the
Company to immediately redeem the outstanding portion of this Debenture in
accordance with clause (y) of Section 6 hereof.

         5. A. (i) Notwithstanding any other provision hereof to the contrary,
at any time prior to the Conversion Date, the Company shall have the right to
redeem (a "Redemption") all or any portion of the then outstanding principal
amount of the Debentures then held by the Holder in cash for an amount (the
"Redemption Amount") equal to (x) the Applicable Redemption Percentage (as
defined below) of the outstanding principal of such Debenture being redeemed (y)
plus all accrued but unpaid interest thereon through the date the Redemption
Amount is paid to the Holder (the "Redemption Payment Date").

               (ii) If the Company elects to make a Redemption, the Company
shall give written notice thereof to the Holder (the "Notice of Redemption").
The Redemption Payment Date shall be the date which is seven (7) business days
after the Holder's receipt of the Notice of Redemption. Anything in the other
provisions of this Debenture, including, but not limited to the preceding
provisions of this Section 5, to the contrary notwithstanding, with respect to
any Debentures for which a Notice of Redemption is given, the Holder shall have
the right, exercisable by giving a Notice of Conversion submitted to the Company
within five (5) business days of the Holder's receipt of the Company's Notice of
Redemption, to convert any or all of the Debentures sought to be redeemed (a
"Redemption Notice Conversion") and the Redemption Notice Conversion shall take
precedence over the redemption contemplated by the Notice of Redemption. Such
Debentures shall be converted in accordance with the terms hereof.

               (iii) The Redemption Amount shall, unless otherwise agreed to
in writing by the Holder after receiving the Notice of Redemption, be paid
to the Holder by wire transfer of good funds on the Redemption Payment
Date.

               (iv) In the event payment of the Redemption Amount is not timely
made, the Holder shall have the right, in the Holder's sole discretion, to
determine that (i) any rights of the Company to redeem outstanding Debentures
shall terminate, and/or (ii) the Notice of Redemption shall be null and void.


                                       4
<PAGE>   5


                           (v) The "Applicable Redemption Percentage" means, if
the Redemption Payment Date is (x) not more than one hundred twenty (120) days
after the Closing Date, one hundred twenty-three and thirty-three one hundredths
percent (123.33%); (y) more than one hundred twenty (120) but not more than one
hundred eighty (180) days after the Closing Date, one hundred twenty-eight and
thirty-three one hundredths percent (128.33%); and (z) more than one hundred
eighty (180) days after the Closing Date, one hundred thirty-three and
thirty-three one hundredths percent (133.33%).

         6. The Holder recognizes that the Company may be limited in the number
of shares of Common Stock it may issue by (X) reason of its authorized shares,
or (Y) the applicable rules and regulations of the principal securities market
on which the Common Stock is listed or traded (collectively, the "Cap
Regulations"). Without limiting the other provisions hereof, (i) the Company
will take all steps reasonably necessary to be in a position to issue shares of
Common Stock on conversion of the Debentures without violating the Cap
Regulations and (ii) if, despite taking such steps, the Company still can not
issue such shares of Common Stock without violating the Cap Regulations, the
Holder of this Debenture (to the extent the same can not be converted in
compliance with the Cap Regulations (an "Unconverted Debenture"), shall have the
option, exercisable in the Holder's sole and absolute discretion, to elect any
one of the following remedies:

                  (x) if permitted by the Cap Regulations, require the Company
         to issue shares of Common Stock in accordance with such Holder's Notice
         of Conversion relating to the Unconverted Debenture at a conversion
         purchase price equal to the average of the closing bid price per share
         of Common Stock for any five (5) consecutive trading days (subject to
         the equitable adjustments for certain events occurring during such
         period as provided in this Debenture) during the sixty (60) trading
         days immediately preceding the date of the Notice of Conversion; or

                  (y) require the Company to redeem each Unconverted Debenture
         for an amount (the "Redemption Amount"), payable in cash, equal to the
         sum of (i) one hundred thirty-three and thirty-three one hundredths
         percent (133.33%) of the principal of an Unconverted Debenture, plus
         (ii) any accrued but unpaid interest thereon through and including the
         date (the "Redemption Date") on which the Redemption Amount is paid to
         the Holder.

The holder of an Unconverted Debenture may elect one of the above remedies with
respect to a portion of such Unconverted Debenture and the other remedy with
respect to other portions of the Unconverted Debenture. Anything herein to the
contrary notwithstanding, the remedy contained in clause (x) or (y) of this
Section 6 shall not be available to the Holder until after the earlier of (i)
the Company's Annual Meeting of Shareholders during calendar year 2001 or
earlier special meeting of shareholders held after the Initial Closing Date,
(ii) two hundred ten (210) days after the date hereof, or (iii) the expiration
of sixty (60) days from the date a holder of any of the Debentures in this
series has exercised a right pursuant to which the last share of


                                       5
<PAGE>   6


Common Stock issuable under the Cap Regulations is to be issued. If prior to
such date, the Cap Regulations no longer apply to limit the Company's issuance
of shares of Common Stock in connection with the Securities or the transactions
contemplated by the Transaction Agreements, the remedies contained clauses (x)
and (y) of this Section 6 shall not be exercisable by the Holder.

         7. Subject to the terms of the Securities Purchase Agreement, no
provision of this Debenture shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of, and interest on,
this Debenture at the time, place, and rate, and in the coin or currency, herein
prescribed. This Debenture and all other Debentures now or hereafter issued of
similar terms are direct obligations of the Company.

         8. A. The obligations of the Company under this Debenture are secured
under the terms of the Securities Purchase Agreement, including, but not
necessarily limited to, the provisions of Section 4(i) thereof and Annex VII
thereto.

            B. No recourse shall be had for the payment of the principal
of, or the interest on, this Debenture, or for any claim based hereon, or
otherwise in respect hereof, against any incorporator, shareholder, officer or
director, as such, past, present or future, of the Company, whether by virtue of
any constitution, statute or rule of law, or by the enforcement of any
assessment or penalty or otherwise, all such liability being, by the acceptance
hereof and as part of the consideration for the issue hereof, expressly waived
and released. This Debenture is a recourse obligation of the Company.

         9. If the Company merges or consolidates with another corporation or
sells or transfers all or substantially all of its assets to another person and
the holders of the Common Stock are entitled to receive stock, securities or
property in respect of or in exchange for Common Stock, then as a condition of
such merger, consolidation, sale or transfer, the Company and any such
successor, purchaser or transferee agree that the Debenture may thereafter be
converted on the terms and subject to the conditions set forth above into the
kind and amount of stock, securities or property receivable upon such merger,
consolidation, sale or transfer by a holder of the number of shares of Common
Stock into which this Debenture might have been converted immediately before
such merger, consolidation, sale or transfer, subject to adjustments which shall
be as nearly equivalent as may be practicable. In the event of any proposed
merger, consolidation or sale or transfer of all or substantially all of the
assets of the Company (a "Sale"), the Holder hereof shall have the right to
convert by delivering a Notice of Conversion to the Company within fifteen (15)
days of receipt of notice of such Sale from the Company. In the event the Holder
hereof shall elect not to convert, the Company may prepay all outstanding
principal and accrued interest on this Debenture by paying the Redemption Amount
contemplated by Section 5(A) hereof, less all amounts required by law to be
deducted, upon which tender of payment following such notice, the right of
conversion shall terminate.


                                       6
<PAGE>   7


         10. If, for any reason, prior to the Conversion Date or the Redemption
Payment Date, the Company spins off or otherwise divests itself of a part of its
business or operations or disposes all or of a part of its assets in a
transaction (the "Spin Off") in which the Company does not receive compensation
for such business, operations or assets, but causes securities of another entity
(the "Spin Off Securities") to be issued to security holders of the Company,
then the Company shall cause (i) to be reserved Spin Off Securities equal to the
number thereof which would have been issued to the Holder had all of the
Holder's Debentures outstanding on the record date (the "Record Date") for
determining the amount and number of Spin Off Securities to be issued to
security holders of the Company (the "Outstanding Debentures") been converted as
of the close of business on the trading day immediately before the Record Date
(the "Reserved Spin Off Shares"), and (ii) to be issued to the Holder on the
conversion of all or any of the Outstanding Debentures, such amount of the
Reserved Spin Off Shares equal to (x) the Reserved Spin Off Shares multiplied by
(y) a fraction, of which (I) the numerator is the principal amount of the
Outstanding Debentures then being converted, and (II) the denominator is the
principal amount of the Outstanding Debentures.

         11. If, at any time while any portion of this Debenture remains
outstanding, the Company effectuates a stock split (but not a reverse stock
split) of its Common Stock or issues a dividend on its Common Stock consisting
of shares of Common Stock, the Fixed Conversion Price shall be equitably
adjusted to reflect such action. By way of illustration, and not in limitation,
of the foregoing, (i) if the Company effectuates a 2:1 split of its Common
Stock, thereafter, with respect to any conversion for which the Company issues
the shares after the record date of such split, the Fixed Conversion Price shall
be deemed to be one-half of what it had been calculated to be immediately prior
to such split; and (ii) if the Company declares a stock dividend of one share of
Common Stock for every 10 shares outstanding, thereafter, with respect to any
conversion for which the Company issues the shares after the record date of such
dividend, the Fixed Conversion Price shall be deemed to be the amount of such
Fixed Conversion Price calculated immediately prior to such record date
multiplied by a fraction, of which the numerator is the number of shares (10)
for which a dividend share will be issued and the denominator is such number of
shares plus the dividend share(s) issuable or issued thereon (11).

         12. All payments contemplated hereby to be made "in cash" shall be made
in immediately available good funds in such coin or currency of the United
States of America as at the time of payment is legal tender for payment of
public and private debts. All payments of cash and each delivery of shares of
Common Stock issuable to the Holder as contemplated hereby shall be made by wire
transfer to the account designated by the Holder or, if no such account is
designated, at the address last appearing on the Debenture Register of the
Company as designated in writing by the Holder from time to time; except that
the Holder can designate, by notice to the Company, a different account or
delivery address for any one or more specific or for all remaining payments or
deliveries.


                                       7
<PAGE>   8


         13. The Holder of the Debenture, by acceptance hereof, agrees that this
Debenture is being acquired for investment and that such Holder will not offer,
sell or otherwise dispose of this Debenture or the Shares of Common Stock
issuable upon conversion thereof except under circumstances which will not
result in a violation of the Act or any applicable state Blue Sky or foreign
laws or similar laws relating to the sale of securities.

         14. This Debenture shall be governed by and construed in accordance
with the laws of the State of New York. Each of the parties consents to the
jurisdiction of the federal courts whose districts encompass any part of the
City of New York or the state courts of the State of New York sitting in the
City of New York in connection with any dispute arising under this Debenture and
hereby waives, to the maximum extent permitted by law, any objection, including
any objection based on forum non coveniens, to the bringing of any such
proceeding in such jurisdictions. To the extent determined by such court, the
Company shall reimburse the Holder for any reasonable legal fees and
disbursements incurred by the Holder in enforcement of or protection of any of
its rights under any of this Debenture.

         15. The following shall constitute an "Event of Default":

                  a.       The Company shall default in the payment of principal
                           or interest on this Debenture and same shall continue
                           for a period of five (5) days after notice thereof
                           from or on behalf of the Holder; or

                  b.       Any of the representations or warranties made by the
                           Company herein, in the Securities Purchase Agreement,
                           or in any of the other Transaction Agreements or in
                           any certificate or financial or other written
                           statements heretofore or hereafter furnished by the
                           Company in connection with the execution and delivery
                           of this Debenture or the Securities Purchase
                           Agreement shall be false or misleading in any
                           material respect at the time made; or

                  c.       The Company fails to issue shares of Common Stock to
                           the Holder or to cause its Transfer Agent to issue
                           shares of Common Stock upon exercise by the Holder of
                           the conversion rights of the Holder in accordance
                           with the terms of this Debenture, fails to transfer
                           or to cause its Transfer Agent to transfer any
                           certificate for shares of Common Stock issued to the
                           Holder upon conversion of this Debenture and when
                           required by this Debenture and such transfer is
                           otherwise lawful, or fails to remove any restrictive
                           legend or to cause its Transfer Agent to transfer on
                           any certificate or any shares of Common Stock issued
                           to the Holder upon conversion of this Debenture as
                           and when required by this Debenture, the Securities
                           Purchase Agreement or the Registration Rights
                           Agreement and such legend removal is otherwise
                           lawful, and any such failure shall


                                       8
<PAGE>   9


                           continue uncured for five (5) business days after
                           written notice from the Holder of such failure; or

                  d.       The Company shall fail to perform or observe, in any
                           material respect, any other covenant, term,
                           provision, condition, agreement or obligation of any
                           Debenture in this series and such failure shall
                           continue uncured for a period of thirty (30) days
                           after written notice from the Holder of such failure;
                           or

                  e.       The Company shall fail to perform or observe, in any
                           material respect, any covenant, term, provision,
                           condition, agreement or obligation of the Company
                           under the Securities Purchase Agreement or the
                           Registration Rights Agreement and such failure shall
                           continue uncured for a period of thirty (30) days
                           after written notice from the Holder of such failure
                           (other than a failure to cause the Registration
                           Statement to become effective no later than the
                           Required Effective Date, as defined and provided in
                           the Registration Rights Agreement, as to which no
                           such cure period shall apply); or

                  f.       The Company shall (1) admit in writing its inability
                           to pay its debts generally as they mature; (2) make
                           an assignment for the benefit of creditors or
                           commence proceedings for its dissolution; or (3)
                           apply for or consent to the appointment of a trustee,
                           liquidator or receiver for its or for a substantial
                           part of its property or business; or

                  g.       A trustee, liquidator or receiver shall be appointed
                           for the Company or for a substantial part of its
                           property or business without its consent and shall
                           not be discharged within sixty (60) days after such
                           appointment; or

                  h.       Any governmental agency or any court of competent
                           jurisdiction at the instance of any governmental
                           agency shall assume custody or control of the whole
                           or any substantial portion of the properties or
                           assets of the Company and shall not be dismissed
                           within sixty (60) days thereafter; or

                  i.       Any money judgment, writ or warrant of attachment, or
                           similar process in excess of Fifty Thousand ($50,000)
                           Dollars in the aggregate shall be entered or filed
                           against the Company or any of its properties or other
                           assets and shall remain unpaid, unvacated, unbonded
                           or unstayed for a period of sixty (60) days or in any
                           event later than five (5) days prior to the date of
                           any proposed sale thereunder; or

                  j.       Bankruptcy, reorganization, insolvency or liquidation
                           proceedings or other proceedings for relief under any
                           bankruptcy law or any law for the relief


                                       9
<PAGE>   10


                           of debtors shall be instituted by or against the
                           Company and, if instituted against the Company, shall
                           not be dismissed within sixty (60) days after such
                           institution or the Company shall by any action or
                           answer approve of, consent to, or acquiesce in any
                           such proceedings or admit the material allegations
                           of, or default in answering, a petition filed in any
                           such proceeding; or

                  k.       The Company shall have its Common Stock suspended or
                           delisted from an exchange or over-the-counter market
                           from trading for in excess of five (5) trading days.

Then, or at any time thereafter, and in each and every such case, unless such
Event of Default shall have been waived in writing by the Holder (which waiver
shall not be deemed to be a waiver of any subsequent default) at the option of
the Holder and in the Holder's sole discretion, the Holder may consider this
Debenture immediately due and payable, without presentment, demand, protest or
notice of any kinds, all of which are hereby expressly waived, anything herein
or in any note or other instruments contained to the contrary notwithstanding,
and the Holder may immediately enforce any and all of the Holder's rights and
remedies provided herein or any other rights or remedies afforded by law.

         16. Nothing contained in this Debenture shall be construed as
conferring upon the Holder the right to vote or to receive dividends or to
consent or receive notice as a shareholder in respect of any meeting of
shareholders or any rights whatsoever as a shareholder of the Company, unless
and to the extent converted in accordance with the terms hereof.

         17. In the event for any reason, any payment by or act of the Company
or the Holder shall result in payment of interest which would exceed the limit
authorized by or be in violation of the law of the jurisdiction applicable to
this Debenture, then ipso facto the obligation of the Company to pay interest or
perform such act or requirement shall be reduced to the limit authorized under
such law, so that in no event shall the Company be obligated to pay any such
interest, perform any such act or be bound by any requirement which would result
in the payment of interest in excess of the limit so authorized. In the event
any payment by or act of the Company shall result in the extraction of a rate of
interest in excess of a sum which is lawfully collectible as interest, then such
amount (to the extent of such excess not returned to the Company) shall, without
further agreement or notice between or by the Company or the Holder, be deemed
applied to the payment of principal, if any, hereunder immediately upon receipt
of such excess funds by the Holder, with the same force and effect as though the
Company had specifically designated such sums to be so applied to principal and
the Holder had agreed to accept such sums as an interest-free prepayment of this
Debenture. If any part of such excess remains after the principal has been paid
in full, whether by the provisions of the preceding sentences of this Section 17
or otherwise, such excess shall be deemed to be an interest-free loan from the
Company to the Holder, which loan shall be payable immediately upon demand by
the


                                       10
<PAGE>   11


Company. The provisions of this Section 17 shall control every other provision
of this Debenture.

         18. This Debenture amends the Company's 6% Secured Convertible
Debenture Due June 7, 2002, dated June 7, 2000, issued to Sherman LLC, in the
original principal amount of US$4,353,652.00, and as so amended, is a
restatement of that Debenture.


                                       11
<PAGE>   12
         IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed by an officer thereunto duly authorized.

Dated: January 25, 2001

                                      CORZON, INC., formerly known as
                                      TANNER'S RESTAURANT GROUP, INC.



                                      By:    /s/ Lawrence Shatsoff
                                      Name:  Lawrence Shatsoff
                                      Title: President


The undersigned acknowledges security interest associated with this Debenture.

B4B COMMUNICATIONS, LTD.

By:    /s/ Lawrence Shatsoff
Name:  Lawrence Shatsoff
Title: Vice President


<PAGE>   13


                                    EXHIBIT A


                              NOTICE OF CONVERSION

   (To be Executed by the Registered Holder in order to Convert the Debenture)


         The undersigned hereby irrevocably elects to convert $______________
of the principal amount of the Secured Convertible Debenture No._____________
(the "Debenture") of CORZON, INC. (the "Company") into Shares of Common
Stock of the Company according to the conditions of the Debenture, as of the
date written below.


Conversion Date*



Applicable Conversion Price




Signature


                            [Name]

Address:





*If this conversion converts the entire remaining principal of this Debenture,
the original Debenture must be received by the Company by the fifth business
date following the Conversion Date.