Spaghetti Casserole
["2 Tbsp. vegetable oil", "1 lb. Italian sausage, cut into pieces", "1 small onion, chopped", "1 can sliced mushrooms", "1 large can stewed tomatoes", "salt and pepper", "1 lb. spaghetti, cooked", "1 pkg. Mozzarella cheese slices", "3 Tbsp. grated Parmesan cheese"]
["Brown sausage in oil over medium heat for 10 minutes.", "Add onions, mushrooms and tomatoes.", "Season with salt and pepper. Cook, uncovered, over low heat for 30 minutes, stirring occasionally."]
["vegetable oil", "Italian sausage", "onion", "mushrooms", "tomatoes", "salt", "Mozzarella cheese slices", "Parmesan cheese"]