Ratatouille is a French Provençal vegetable stew dish (the full name of the dish is ratatouille niçoise) originating in Nice, France.
Its traditional ingredients include: tomatoes, garlic, onions, zucchini, eggplant, bell peppers, and may include such herb combinations as marjoram and basil, bay leaves and thyme, or a mixture of Herbes de Provence, which may contain such herbs as savory, fennel, basil, thyme, and lavender leaves et al.
Ratatouille can be prepared by sauteéing, layering the ingredients together as a casserole, or simmering in a large cooking pot. It is usually served as a side dish, but it can be served as an entreé, accompanied by pasta, rice or bread.