1 1/2 lbs. ground beef
1 c. chopped onion
1 lg. jar spaghetti sauce
1 lg. can mushrooms
8 oz. spaghetti (cooked, broken and drained)
2 c. Mozzarella cheese (grated)
1/3 c. Parmesan cheese

Brown ground beef and onion. Mix ground beef, onion, sauce, mushrooms, spaghetti. Place 1/2 mixture in a 9x13 pan. Sprinkle with Mozzarella cheese. Top with rest of the spaghetti mixture. Top with Parmesan cheese. Bake at 375 degrees for 30 minutes.