POTATOE CASSEROLE

1 large bag of frozen hash brown potatoes
1 (10 3/4 oz) can cream of chicken soup
2 cups sour cream
2 cups sharp cheddar cheese, grated
1/2 cup onion, chopped
crushed cornflakes
butter

Combine, potatoes, soup, sour cream. and onion and put in a greased 3-quart baking dish. Top with crushed cornflakes. Dot with butter. bake at 325 degrees for 30 minutes or until hot and bubbly.