Hashbrown Casserole

I got this recipe from my sister in law last year.  I make it all the time.  It goes well with so many main dishes.  I think I have heard it called company potatoes in the past.  This recipe makes alot and it great reheated.

Hash Brown Potato Casserole

36 oz. pkg frozen hash brown potatoes
1/2 cup melted butter
salt and pepper (to taste)
1/2 cup chopped onions
1 can cream of celery soup
16 oz. sour cream
3 cups grated cheddar cheese

Topping:
3 cups frosted corn flakes
1/3 cup melted butter

    Mix all ingredients (except topping) in large bowl. Grease 9 x 13 pan. Put ingredients in pan. Mix topping. Put layer of topping on top.
    Bake uncovered at 350° for 45 minutes until hot and bubbly.