Preheat oven to 400
Sauté onion in large pan, add garlic and sauté till fragrant. Add whole jar of tomato sauce, cover and let simmer.
While sauce simmers, slice eggplants into 0.5” discs. Slice discs in half to make half moons.
Put sliced eggplants into large baking disk. Pour sauce over top and toss.
Top with mozzarella, then bread crumbs, then parmesan cheese.
Bake covered with foil for 30 minutes or until eggplant is cooked through. Remove foil and cook 3-5 more minutes till cheese is bubbly.