Preheat the oven to 180 (400 degrees f) Finely dice the onion and mince the garlic. Sauté both in a skillet with olive oil until softened (about five minutes).

While the onion and garlic are sautéing, thinly slice the rest of the vegetables.

Spray the inside of an 8x8 square or round baking dish with non-stick spray. Spread the softened onion and garlic in the bottom of the dish. Place the thinly sliced vegetables in the baking dish vertically, in an alternating pattern. Sprinkle generously with salt, pepper, and thyme.

Cover the dish with foil and bake for 30 minutes. Remove the foil, top with cheese and bake for another 15-20 minutes or until the cheese is golden brown