Cook the onions in butter. Stir together the hash brown potatoes, onion, melted butter, sour cream, cream of chicken soup, garlic powder, salt, pepper, cheddar, and Monterey jack. Then, spoon the mixture into a prepared dish.
1
Stir together the melted butter and crushed cornflakes and sprinkle over the potatoes.
2
Bake and serve.
3