Slice eggplant, zucchini, tomato, and onion thinly and set aside.
Heat olive oil in a pan and sauté minced garlic and onion.
Add tomato sauce to the pan and bring to a simmer.
Spread the tomato sauce in an oven dish, then layer the sliced vegetables on top.
Season with salt, pepper, and herbs.
Cover with foil and bake in a preheated oven at 180°C for 30 minutes.
Remove the foil and bake for another 10 minutes.
Serve the finished ratatouille on a plate.