1 (2 lb.) pkg. frozen hash browns, thawed
2 cans cream of potato soup
1 (16 oz.) carton sour cream
2 c. grated Cheddar cheese
1 c. Parmesan cheese
1 can French fried onion rings

Combine all ingredients except onion rings and stir well. Pour into buttered 9x13 inch pan. Bake at 350 degrees for 40 minutes. Top with 1 can French fried onion rings and return to oven for 5 minutes.