Potato Casserole

2 lbs. thawed hash browns
2 T. chopped onion
1/2 cup butter
1 can cream of chicken soup
1 tsp. salt
1 pint sour cream
1/2 tsp. pepper
2 cups shredded cheese

Mix all ingredients in a bowl and pour into a greased 9x13 dish. Top with the following: 2 cups corn flakes and 1/4 cup melted butter. Bake for 45 minutes in a 350 degree oven.