1 lb. ground beef
1 med. onion
1 1/2 lb. zucchini (sliced & cooked)
1/2 lb. American cheese
1 can reg. cream of mushroom soup
Cracker crumbs, optional

Saute ground beef and chopped onion. Add soup. Layer baking dish with 1/2 of zucchini. Top with half of ground beef mixture and 1/2 of cheese. Repeat. Sprinkle with cracker crumbs if desired. Bake at 300 degrees for an hour.