Prepare the vegetables. Slice the zucchini, eggplants, and potatoes into rounds. Soak the eggplant and zucchini in salted water for 15 minutes, then rinse.

Bring the tomatoes to a boil. Sauté the chopped onion in a drizzle of olive oil, then add the bell pepper cut into small cubes. Season with salt and pepper. Grate the tomatoes and add 1 tablespoon tomato paste, chopped parsley, thyme, Herbes de Provence, 2 tablespoons olive oil, chopped garlic, salt, and pepper. Pour in this sauce and cook for 3 minutes.

Bake at 400°F (200°C) for 40 to 45 minutes. Remove the aluminum foil for the last 15 minutes, until the vegetables are tender.