Hash Brown Casserole

Ingredients

• 1/2 stick butter or margarine
• 1 medium onion, chopped
• 1 (8 oz.) carton sour cream
• 1 (10 oz.) pkg. grated Cheddar cheese
• 1 (8 oz.) carton sour cream with chives
• 1 (10 3/4 oz.) can cream of chicken soup
• 1 (10 3/4 oz.) can cream of mushroom soup
• 1 (2 lb.) pkg. frozen hash brown potatoes
• 1/2 c. cornflakes, crushed