Funeral Potatoes (Grandma Johnson)

put a 2 lb pkg of thawed frozen hash brown potatoes in a 9x13 greased pan.
Mix 1 small onion, diced, 1 c cream of celery soup, 1 16oz Sour Cream, 1 cube butter melted, 2 c grated cheese, and a little milk.
Spread over hash browns. Top with 1/2 c grated cheese.
bake at 350 deg for 1/2 hr