Mahmud Nasir (Omid Djalili) is a loving husband, doting father and something of a "relaxed" Muslim. His son Rashid Nasir (Amit Shah) wishes to get married but to do so, the Nasir family must receive the blessing of his fiancee's new stepfather, a devout Muslim cleric. Trying to act the devout family is made that much more difficult by the revelation that Mahmud was adopted as a baby and born Jewish - his real name is Solly Shimshillewitz. As Mahmud tumbles headlong into a full scale identity crisis, the only person he can turn to for help is Lenny Goldberg (Richard Schiff), a drunken Jewish-American cabbie who agrees to give Nasir/Shimshillewitz lessons in becoming a Jew. Mahmud does this so he can get a Rabbi (Matt Lucas) to agree to let him see his dying biological father, Issy Shimshillewitz.