1 (32 oz.) bag frozen hash browns
3/4 c. melted butter
1/2 c. chopped onion
1 can cream of mushroom soup
1 (8 oz.) carton sour cream
1 c. shredded Cheddar cheese
2 c. corn flakes

Let hash browns thaw. Combine 1/2 cup butter, onion, soup, sour cream and cheese. Add hash browns. Pour into greased casserole dish. Mix 1/4 cup butter and corn flakes. Place on top of potatoes. Bake at 350 degrees for 50 minutes.