Heat the olive oil in a large skillet over medium heat. Add the onion and garlic and sauté until the onion is softened and lightly browned, about 5 minutes.
Add the eggplant, bell peppers, zucchini, and tomatoes and sauté for 10 minutes, stirring occasionally.
Stir in the tomato paste, thyme, oregano, and salt and pepper to taste. Reduce the heat to low and simmer, stirring occasionally, for 30 minutes, or until the vegetables are tender.
Stir in the parsley and serve hot or cold.
Interesting Facts
Ratatouille is a classic Provençal dish, originating in Nice, France.
It is traditionally served with rice, pasta, or potatoes.
It can also be served as a side dish or as a main course.