Cheese Potatoes (Funeral potatoes)

6 potatoes, large, cooked and peeles
2 cans Cream of Chicken soup
1  can evaporated milk, or 2 cups sour cream*
1/2 cup each butter, onion, cheese, cornflakes (optional)
* my preference
Mix  soup, milk, or sour cream, butter, onin, and cheese.  Salt and  pepper to taste.  Heat  sauce andpour over grated cooked potatoes.  Sprinkle with cornflakes (I don't) Bake 350 45 minutes