Baked Stuffed Shells
["1 c. chopped onion", "1/2 lb. ground beef", "1 (15 oz.) can tomato sauce", "1 small can tomato paste", "1/2 tsp. salt", "1/2 tsp. oregano", "1/4 tsp. pepper", "1 1/2 c. cottage cheese", "1 large egg", "1/4 c. Parmesan cheese", "2 Tbsp. chopped parsley", "4 oz. jumbo macaroni shells", "1 can mushrooms, sliced or whole"]
["Saute onion, beef and all other ingredients, except cottage cheese, egg, parsley, Parmesan cheese and mushrooms.", "Simmer about 15 minutes.", "Cook shells as directed; cool.", "Fill shells with cheese mixture:", "cottage cheese, egg, Parmesan cheese and parsley. Place sauce in 2-quart baking dish.", "Add stuffed shells.", "Bake for 30 minutes at 300\u00b0.", "Serves 6."]
["onion", "ground beef", "tomato sauce", "tomato paste", "salt", "oregano", "pepper", "cottage cheese", "egg", "Parmesan cheese", "parsley", "jumbo macaroni", "mushrooms"]