2 lb. bag hash brown potatoes, thawed
1/2 c. melted butter
1/2 pt. sour cream
1/2 c. chopped onion
1 can cream of chicken soup
2 c. grated mild cheddar cheese
1 tsp. salt
1/2 tsp. black pepper

TOPPING:

1 stick butter, melted
2 c. cornflake crumbs

Mix all ingredients, except topping ingredients, and pour into 11 x 13 dish. Sprinkle topping over casserole. Bake uncovered at 350 degrees for 45 minutes.