A funny thing happened on the way to the kitchen

Show up and be yourself -- and get paid to do it.

That’s the job description Patton Oswalt accepted when he was cast as the lead voice in the new Pixar/Disney film, “Ratatouille.”

The film revolves around a rat named Remy (Oswalt) who dreams of becoming a master chef at a five-star restaurant in Paris. The voice of Remy had been difficult to cast, but then one day writer-director Brad Bird heard a routine of Oswalt’s on the radio.

“I was talking about the Black Angus Steak House.... and how they assault you with food,” says the stand-up comic and actor who played Spence Olchin for six seasons on the CBS sitcom “King of Queens.” “That enthusiasm is what he wanted, I guess.”

And while Remy may be French, he sounds exactly like Oswalt. “They stressed ‘don’t do a character,’ ” Oswalt says. “That was really cool.”

That off-beat take on voice casting runs throughout “Ratatouille” -- and against the grain in the world of voice-over animation.

When Robin Williams was cast as the fast-talking Genie in Disney’s 1992 hit, “Aladdin,” the world of voice-over animation was forever changed: Though veteran voice actors are still called upon to work on animated series and feature films, it’s more the norm these days that studios vie to get A-list talent to lend their vocal prowess. Whether it is the “Shrek” franchise or even last year’s Oscar-winning “Happy Feet,” the majority of animated films are sold to audiences through the star quality of the vocal talent.

But Bird, the writer-director of “Iron Giant” and the Oscar-winning “The Incredibles,” tends to veer from the norm.

“I question the thinking that people go to animated films to listen to celebrities,” he says. “I think that is a placebo that makes the people selling the movie feel better. There is actually almost no correlation between how famous the voice is and box office success.”

That’s not to say he totally eschews household names -- after all, “Ratatouille” casts Peter O’Toole as the voice of a pompous food critic named Anton Ego, as well as Emmy-winning actor Brad Garrett. Janeane Garofalo is the voice of Colette, a serious-minded young chef with an “Amelie”-style bob who works at a Parisian eatery, Gusteau’s, that has seen better days.

But the heart of “Ratatouille” belongs to Oswalt and Lou Romano, who was the production designer on “The Incredibles,” and was cast to voice the significant role of Linguini, an orphan boy who also works at Gusteau’s and becomes pals with Remy.

Garofalo didn’t even know her character was French when she was hired. “I had a CD of a guy speaking French, so I mimicked him.”

So does she have anything in common with Colette?

“Nothing,” she quips. “She’s an animated character, and I wish my hair looked like that. I have never seen the health and the shine of that hair before. I wish I had a Vespa scooting around Paris.”

Oswalt believes being stand-up comics was beneficial to him and Garofalo because “we were able to see very early that this script was great. And what made our performances better is if we got out of the way of the screenplay. It is a Brad Bird script, and I wanted to read it as is, instead of going, ‘I have to get my big peanut-butter fingerprints all over this.’ I was excited not to do anything to it.”

Though he’s done voice-over work on numerous animated programs, including “Static Shock” and “SpongeBob SquarePants,” he says playing Remy was just in “another league.”

“The fact that you are getting directed by Brad Bird,” says Oswalt. “He totally just completely gets into it and gets everybody wrapped up into his enthusiasm.”

susan.king@latimes.com