1 stick butter
1 onion, chopped
1 (2 lb.) bag frozen hash browns, thawed
1 can cream of chicken soup
1 pt. sour cream
2 c. shredded Cheddar cheese
3/4 c. crushed corn flakes

Spray a 9 x 13 inch glass pan with cooking spray. Saute onion in butter. Mix together all ingredients, except corn flakes. Spoon mixture evenly into pan. Bake at 375 degrees for 50 minutes or until hot and bubbly. Sprinkle corn flakes atop casserole and bake 10 additional minutes.