Question: What cafeteria worker voiced by a soul singer returned in the 140th episode of South Park ?

Context articles: Great X-Pectations
Chef Aid: The South Park Album
The Return of Chef
Change of Heart (Star Trek: Deep Space Nine)
I'm a Little Bit Country
Chef (South Park)
Good Shepherd (Star Trek: Voyager)
Knock 'Em Down
The Biggest Douche in the Universe
Hush, Hush, Sweet Liars

"Great X-Pectations" is an episode from the sitcom "A Different World", and was first broadcast on July 9, 1993 on NBC.
 Written by Jeanette Collins & Mimi Friedman and directed by Glynn Turman, it is the 20th episode of the sixth season, and the 140th episode of the series.
 Moreover, it is the final episode of the series to air on NBC before the end of its run.
 Several additional episodes remain unaired until years later, when the series is in syndication.
Chef Aid: The South Park Album is a 1998 soundtrack/compilation album based on the American animated comedy series "South Park".
 Several well-known artists perform on the record, which was mainly produced by Rick Rubin.
 "Chef Aid" contains a number of songs from and inspired by the show, while other songs are largely independent from "South Park".
 The album was released during the show's second season, shortly after the broadcast of the episode called "Chef Aid", which features many of the stars and songs that appear on the recording.
 Soul singer Isaac Hayes appears in character as Chef throughout the album, which mimicks a live concert.
"The Return of Chef" is the first episode in the tenth season of the American animated television series "South Park".
 The 140th episode of the series overall, it first aired on Comedy Central in the United States on March 22, 2006.
 The episode was the first after the departure of actor Isaac Hayes, who voiced the character Chef.
 Hayes, a Scientologist, left after a falling-out with the creators over their treatment of Scientology in the previous season's episode "Trapped in the Closet".
 Scientology has been accused of using brainwashing techniques, and the episode portrays Chef as having been brainwashed.
"Change of Heart" is the 16th episode of the of "", the 140th episode overall.
"I'm a Little Bit Country" (also known as "The South Park KICK-ASS 100th episode TV special") is the fourth episode of the seventh season of the American animated television series "South Park", and the 100th episode of the series overall.
 It originally aired on Comedy Central in the United States on April 9, 2003.
 The episode title is based on the song "I'm a Little Bit Country" by Marty Cooper, as made famous by Donny and Marie Osmond.
Jerome "Chef" McElroy is a cartoon character on the Comedy Central series "South Park" who was voiced by soul singer Isaac Hayes.
 A cafeteria worker (as his nickname implies) at the local elementary school in the town of South Park, Colorado, Chef is generally portrayed as more level-headed than the other adult residents of the town, and sympathetic to the kids.
 His guidance is often sought by the show's core group of child protagonists – Eric Cartman, Stan Marsh, Kyle Broflovski, and Kenny McCormick – as he is usually the only adult whom they consistently trusted.
 To an inadvertent fault, he frequently gives inappropriate advice, usually in the non sequitur form of a lascivious soul song.
"Good Shepherd" is the 140th episode of the science fiction television series "".
 It is the 20th episode of the show’s .
"Knock 'Em Down" is the twentieth episode of the sixth season of the American sitcom "Modern Family", and the series' 140th episode overall.
 It originally aired on April 22, 2015.
 The episode was written by Rick Wiener & Kenny Schwartz, and directed by Beth McCarthy Miller.
"The Biggest Douche in the Universe" is the 15th episode of the sixth season and the 94th overall episode of the Comedy Central animated series "South Park".
 It was first broadcast on November 27, 2002 and was the last in a mini-arc depicting Cartman being occasionally possessed by Kenny.
 The episode is centered on Liane Cartman and Chef attempting to exorcise Kenny's soul while Stan deals with trying to debunk self-proclaimed psychic John Edward, whom the entire crew of South Park Studios agreed to be "the biggest douche in the universe."
 The episode is rated TV-MA in the United States, except on syndicated broadcasts, where the episode is rated TV-14, instead.
"Hush, Hush, Sweet Liars" is the twentieth episode and the season finale of the sixth season and 140th episode overall on the Freeform mystery drama series "Pretty Little Liars".
 The episode was broadcast on March 15, 2016.
 It was written by the series' showrunner I. Marlene King and directed by Ron Lagomarsino.