Preheat oven to 375 degrees.
Using a mandolin or sharp chef’s knife, slice zucchini, tomato and pepper into thin slices. In a skillet or round baking dish, mix tomato sauce with minced garlic, red chili flakes, salt and olive oil. Spread evenly. Layer sliced veggies on top in a spiral stack. Drizzle with olive oil and sprinkle with salt, pepper and rosemary. Bake for 55-60 minutes or until veggies are tender.