Sauté both in a skillet with olive oil until softened (about five minutes).
While the onion and garlic are sautéing, slice the rest of the vegetables.
Spray the inside of a baking dish with non-stick cooking 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, thyme and Italian seasoning.
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.
Garnish with parsley, if desired.
Notes
NOTE: I did not use the same proportions on the vegetables. I used several tomatoes. I used as much of a vegetable as it took to complete the rows.NOTE: Don't cut the tomatoes too thin. They need to be thick enough to hold their shape while baking.NOTE: Martha Stewart includes sprigs of rosemary, thyme, marjoram and oregano.NOTE: You can also layer the onion-garlic mixture over top of the vegetables after sprinkling with seasonings. This will allow the onion and garlic to flavor the vegetables more fully.NOTE: Make sure you test potatoes and ensure they are fork tender before adding cheese.