Tuna Noodle Casserole
["2 Tbsp. margarine or butter", "1/2 c. chopped onion", "1 can cream of mushroom soup", "1/2 c. milk", "2 c. medium egg noodles, cooked", "1 c. cooked peas", "2 (7 oz.) cans tuna", "1/2 c. shredded Cheddar cheese"]
["Combine all ingredients except cheese and pour into 1 1/2-quart casserole.", "Bake for 25 minutes at 400\u00b0.", "Top with cheese and bake another 5 minutes or until cheese is melted."]
["margarine", "onion", "cream of mushroom soup", "milk", "egg noodles", "peas", "tuna", "Cheddar cheese"]