Ratatouille and vegetable tian are two classic French dishes that are both made with a variety of vegetables. Ratatouille is a stew-like dish made with eggplant, zucchini, tomatoes, garlic, onions, bell peppers, and herbs. Vegetable tian is cooked in the oven in a baking dish that consists of layers of thinly sliced vegetables such as eggplant, zucchini, tomatoes, garlic, onions, bell peppers, and herbs.