Ratatouille is one of the few Crock Pot recipes that can be made from foods that have a neutral or negative effect, such as mushrooms and ice, providing a 100% bonus hunger advantage from eating those items separately.
Eating the recipe ingredients cooked will almost always provide more benefits unless one needs a slight Sanity boost, wants to keep preserved food, or makes use the food types above.
Trivia
Ratatouille's meager benefits and low Crock Pot priority implies that it is a sort of "consolation prize" for uncreative Crock Pot recipes.
During the Pig Fiesta event in the Hamlet DLC, Ratatouille takes on a more festive appearance.
Ratatouille is a peasant dish originating from Nice, France. It was a dish prepared by commoners because of the easy-to-come-by ingredients, somewhat reminiscent of how vegetables are often abundant in Don't Starve, especially in early-game.
Bugs
Ratatouille does not exclude Fishes. The Shipwrecked DLC introduces food items that have fish values without any meat value, such as Fish Morsels and Jellyfish. This causes using up to 2 Fish Morsels or using a single Jellyfish in a recipe with Vegetables to produce Ratatouille despite containing meat.