It's a documentary about Kenny Shopsin, who runs a restaurant in NYC that's just as eclectic as the best parts of that city. He has a 900-item menu (check it out online) and a ton of crazy rules--no parties of five is one, and he used to forbid people from ordering the same thing as anyone else, because it bored him to make the same thing he already cooked. It's funny, because all the reviews dwell on how foul-mouthed Kenny is, but either I am immune to profanity by now, or the charming way he delivers a line makes me completely forget if he swore at all.
If you like the movie, WHICH YOU WILL, you need to seek out Kenny's book, "Eat Me." It has recipes, but I sat down and read it like a novel. Just awesome.