Spaghetti Casserole

Ingredients

• 1 1/2 lb. ground beef
• 1 large onion, chopped
• 1 (16 oz.) can tomatoes
• 1 can cream of mushroom soup
• 1 tsp. salt
• 1/8 tsp. pepper
• 2 (5 oz.) cans tomato sauce
• 1 (8 oz.) pkg. thin spaghetti
• 1/2 lb. grated sharp cheese