Prepare all the ingredients: wash all the vegetables thoroughly, peel the eggplants, and cut the vegetables (peppers, zucchini, eggplants, and onions) into evenly-sized cubes to ensure consistent cooking.
3 red peppers, 4 zucchini, 3 eggplants, 2 onion
Grease a large baking tray generously with extra virgin olive oil, or line it with a reusable silicone oven sheet. A silicone sheet is a great alternative to baking paper—it’s washable, reusable, and makes cleaning much easier while preventing sticking.
3 tablespoon extra virgin olive oil
Arrange all the vegetables on the tray. Add the fresh basil leaves (or Provençal herbs if substituting) and garlic.
Season with salt and black pepper, then stir everything well to coat the vegetables evenly.
2 teaspoon salt, 10 leaves fresh basil leaves
Bake the vegetables in the oven at 180°C (350°F) for 30 minutes.
After 30 minutes, remove the tray from the oven and stir the vegetables. This helps them caramelize evenly.
Return the tray to the oven and bake for another 30 minutes.
After the second baking period, add the canned tomato sauce. Stir well to combine, ensuring the sauce coats the vegetables thoroughly.
1 cup tomato sauce Mutti
Increase the oven temperature to 200 C (390F) and place the tray back in the oven and bake for an additional 30 minutes.
Once done, the ratatouille will be soft, creamy, and caramelized, with the vegetables beautifully melded together.
Serve immediately while warm, or refrigerate and serve the next day. The flavors deepen and improve over time, making it an excellent make-ahead dish