Can a rat and a chef work together?

Pixar Animation will serve no rodent before its time.

The outfit behind such animated smashes as “Toy Story,” “Finding Nemo” and “The Incredibles” has a simple secret: It takes its time and lets a story mature to its finest.

That includes the new “Ratatouille,” the tale of a rat that gets an unlikely chance to do what he loves most: cook in a French restaurant in Paris.

Opening today, “Ratatouille” is a rarity in this summer of sequels: An original story with newly created characters that is not based on a comic book, a TV show, a children’s story or anything else that came before.

“I joke about summer sequels and how we made this as the prequel to the sequel,” says writer-director Brad Bird, the Academy Award-winning filmmaker behind “The Incredibles.”

Adds “Ratatouille” producer Brad Lewis: “Ideally, we’ll stand out in the crowd of sequels.

“All this time we pour in getting the story right is something that is a luxury for a producer,” says Lewis, who came to Pixar after working on such films as “Antz.”

“There’s a commitment from the top on down: ‘You guys do what it takes to make the story work.’ In some films, you don’t have that time to actually craft and craft and craft the story.”

“Ratatouille” presents the adorable Remy (voiced by Patton Oswalt), a rodent possessing keen senses of taste and smell compared to his rat brethren, who are content to eat any old garbage.

Remy dreams of following in the footsteps of his deceased hero, human chef Gusteau (Brad Garrett). Circumstance lands Remy at Gusteau’s restaurant, where the spirit of the chef guides him through a bizarre partnership with clumsy clean-up boy Linguini (Lou Romano), who becomes the rat’s accomplice in cooking up delectable dishes.

The voice cast includes Janeane Garofalo as the kitchen’s only female cook, Ian Holm as a devious chef and Peter O’Toole as a Scrooge-like food critic.

John Lasseter, Pixar’s creative mastermind and an executive producer on “Ratatouille,” says the new film follows the same guidelines as the company’s previous hits, which include “A Bug’s Life,” “Toy Story 2,” “Monsters, Inc.” and “Cars.”

Pixar relies on the playbook established by Lasseter’s idol, Walt Disney, whose pioneering animation balanced laughs, thrills, chills and characters that audiences embraced as companions.

“We always believe in what Walt Disney said: ‘For every laughter, there should be a tear.’ We work really hard to find that emotion and pathos,” says Lasseter, whose “Toy Story” started the era of computer-animated feature films,

“By the end, the characters, we know them so well, they’re like friends for us,” he says. “Like fellow Pixarians. They’re so real to us, partly because they are us.”

“Ratatouille” was conceived by Pixar animator Jan Pinkava, who was supposed to make his feature directing debut with the film. After a couple of years of work, the story had not developed to the liking of Pixar’s top brass.

Once Bird finished “The Incredibles,” he began helping out on “Ratatouille,” and Pixar overseers eventually decided to put him in charge.

Taking risks by telling new stories with fresh characters is a key to Pixar’s success, Bird says.

“One of my all-time heroes is the Beatles,” he says. “They had enormous success and every incentive in the world to do the same thing, and their sound never stayed in the same place. They took it as an opportunity to take the audience on a journey with them, trying new things and going in new directions.

“Is there a way you can do this in a more entertaining fashion? Is there a way to get the audience to think you’re going to go left, then suddenly you go right? That’s what makes you excited to get up in the morning.”