The main ingredient in traditional French ratatouille is eggplant, also known as aubergine. Ratatouille is a rustic vegetable dish that typically includes a medley of vegetables such as zucchini, bell peppers, tomatoes, onions, and herbs. The dish is characterized by its vibrant colors and rich flavors, with eggplant serving as a key component that adds creaminess and texture. Traditionally, ratatouille can be prepared in various ways, including sautéing or baking, allowing the vegetables to meld into a delicious, hearty stew. This dish embodies the essence of Provençal cuisine and showcases the bounty of summer vegetables.