1 (32 oz.) frozen hash brown potatoes, thawed
3/4 c. butter
1/2 c. chopped onion
1 can cream of chicken soup
8 oz. sour cream
1 c. shredded cheddar cheese
1/2 to 1 c. cornflake crumbs

Combine potatoes, 1/2 cup butter, onion, soup, sour cream and cheese; stir well. Spoon into a greased 2 1/2-quart casserole or 13x9-inch baking dish. Crush cereal and stir in remaining butter. Sprinkle over potato mixture. Bake at 350 degrees for 50 minutes.