Some will tell you Ratatouille is about a rat who can cook, but I think it’s about a critic who is won over by the quality of a rat’s cooking.
The movie begins with Auguste Gusteau’s premise that “Anyone can cook.”
Gusteau is the chef who originally inspired the movie’s hero, Remy, who emerges from the Parisian sewers to find himself in Gusteau’s kitchen just after Gusteau’s son gets a job as a garbage boy.
But the plot turns on food critic Ego's realization that “not everyone can become a great artist, but a great artist can come from anywhere.”
Whatever else you can say, the folks at Pixar made a rat entertaining and sympathetic. Not everyone can do that.