### Clue: Impromptu time for a sarnie? (3,7)
### Answer: JAM SESSION 
 ### Explanation: JAM(an example,*? * of a type (a filling) of sandwich,*sarnie*) SESSION(*time*, period to have your sandwich?).  Defn:  A *time *when jazz musicians give an *impromptu* performance.  Not sure about "time" doubling up in the wordplay and definition parts of the clue.