Bring 4 quarts water to a boil; add 1 tablespoon salt and unpeeled potatoes. Boil until tender. Allow to cool, then remove peels.
Grate potatoes and set aside (the grating disc of a food processor of a hand grater may be used).
Heat butter and soup; add minced onion, cheese, sour cream, salt and pepper. Stir into potatoes and transfer to a 9x13 inch baking dish.
Microwave cornflakes with 2 tablespoons butter and use to top potatoes. Refrigerate overnight.
Bake at 350°F for 45 to 60 minutes (until top is nicely golden brown).
Submitted by: CM
