Cracker Barrel Old Country Store Hashbrown Side Dish

1 (2 pound) bag frozen hash browns, thawed
1 medium onion, finely chopped
6 tablespoons margarine, melted
1 pound sour cream
8 ounces Cheddar or Colby cheese, shredded
1 can cream of chicken soup
Cornflakes, crushed
4 tablespoons margarine, melted

In a 13 x 9-inch baking pan, make single layers of the following: Potatoes, onions, 6 tablespoons melted margarine, sour cream, Cheddar cheese and soup. Sprinkle top with cornflakes. Drizzle 4 tablespoons margarine over top. Bake at 350 degrees F for 1 hour or until bubbly and piping hot.