Potato Surprise - cooking recipe

Ingredients

1 box au gratin potatoes
1 c. cooked macaroni
1 small onion, chopped
1 can corn, drained
1 can mushrooms, drained
1 Tbsp. butter

Preparation

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.