1. Preheat oven to 350°F. Lightly grease a 13×9 pan; set aside. In a large bowl combine the potatoes, sour cream, onion, cream soup, 1 ½ cups cheese, butter, salt and pepper. Mix well and taste for additional salt and pepper if necessary.
2. Spread into prepared pan and bake uncovered at 350°F for 45 minutes. Optional, set broil to high and let cheese get crusty and bubbly on top for 1-2 minutes.