Bourdain has a long history with “Top Chef,” TV’s best cooking competition, having been a guest judge and blogger for the show on the Bravo Web site. This season was the first where he could serve as a regular judge on “Top Chef: All-Stars” because the show is finally shooting in New York, where Bourdain lives.

“I’m a cooking nerd,” says Bourdain, who still considers himself a chef at heart. “I’m rooting for these people. I admire cooks and it’s sort of thrilling when you see really talented cooks reach the limits of their ability and go beyond. Other times you see really good cooks have a bad day and choke.”

On “Top Chef,” Bourdain is completely and audaciously himself, tossing insults at the lackluster efforts of the chefs. One example: He told the contestant Fabio that his plate of food looked like a dead animal turned inside-out. One of Bourdain’s favorite things about the show has nothing to do with food; it’s about cracking up Tom Colicchio, the show’s chief judge.

“If I seem to be enjoying myself delivering a one-liner on the show, it’s not because I store them up like chestnuts beforehand,” Bourdain says. “It’s because cracking up Mt. Rushmore over there really is fun.”