 After season six , Mirkin suggested Oakley and Weinstein take over as showrunners , but remained on the show in an advisory capacity , helping them with technical aspects of the show such as editing and sound mixing , and attending table readings of the scripts . He was the executive producer for three other episodes from season seven : " Lisa the Vegetarian " , " Radioactive Man " and " Team Homer " . " Lisa the Vegetarian " was approved by Mirkin after the story was pitched by Cohen ; Mirkin had just become a vegetarian himself , and so many of Lisa 's experiences in the episode were based on his own . Mirkin flew to London to record the episode 's guest stars Paul and Linda McCartney at Paul 's recording studio , where the McCartneys spent an hour recording their parts . Mirkin later said that recording with the McCartneys was one of the most " amazing " experiences of his life and considers the episode to be one of his favorites . Mirkin returned to the role of showrunner to produce the episodes " The Joy of Sect " and " All Singing , All Dancing " for season nine . He pitched the plot for " The Joy of Sect " , because he was attracted to the notion of parodies of cults , calling them " comical , interesting and twisted . " 
