2 lb. hash browns (squares), thawed for 30 min.
1 c. chopped onion
1 (16 oz.) sour cream
1 stick butter, melted
8 oz. grated sharp Cheddar cheese

Mix together and top with crushed potato chips, if desired. Bake in oiled 9 x 13 inch pan at 350 degrees for 1 1/2 hours.