In a pan:
1/2 c onion, chopped
1/4 c margarine
Sauté until onions are transparent.
Add:
1 can cream of chicken soup
2 lb frozen hash brown potatoes
2 c sour cream (1 pint)
Spoon into greased 13 x 9 x 2 pan.
Combine:
2 c shredded cheddar cheese
1 c corn flake crumbs
Spread over potatoes.
Bake @ 350, 45 minutes