1 (32 oz.) pkg. frozen hash browns
1 pt. sour cream
1/4 c. chopped onion
2 cans mushroom soup
10 oz. Cheddar cheese
1/2 c. butter

Combine in crock pot, cook on high for 4 hours. Then turn to low until serving. Can be baked in casserole at 350 degrees for 45 minutes. Sprinkle cheese on top and bake a few minutes more.