Potato Surprise
["1 box au gratin potatoes", "1 c. cooked macaroni", "1 small onion, chopped", "1 can corn, drained", "1 can mushrooms, drained", "1 Tbsp. butter"]
["Prepare potatoes as directed on box.", "Before baking, add the remaining ingredients and stir well.", "May have to add a little more milk.", "Bake at 350\u00b0 until potatoes are done."]
["gratin potatoes", "macaroni", "onion", "corn", "mushrooms", "butter"]