2 lbs. frozen hash browns
8 oz. shredded cheddar cheese
8 oz. sour cream
1/2 stick butter
1 can cream of mushroom soup
1 lg. chopped onion

Thaw hash browns. Mix together hash browns, cheese, sour cream, butter, soup and onion. Bake in a 9"x13" pan at 350 degrees for 1 hour.