Wash all the vegetables. Slice the eggplant, zucchini, and bell peppers into rounds or small cubes. Peel and thinly slice the onion. Peel and mince the garlic.

In a large skillet, heat 2 tablespoons olive oil (about 30 ml) over medium heat. Add the onion and minced garlic, and sauté until they are soft and translucent.

Add the eggplant and cook for about 5 minutes, stirring occasionally. Then add the zucchini and bell peppers. Cook for another 10 minutes, stirring regularly.

Add the diced tomatoes, thyme, and bay leaf. Season with salt and pepper, and mix well. Cover the skillet and simmer on low heat for about 30 minutes, until all the vegetables are tender.