FABULOUS POTATOES

10 medium potatoes, peeled and cut into chunks
2 medium onions, coarsley chopped
8 ounces sour cream
8 oz. cream cheese, softened
1 cup heavy cream
1 cup grated Cheddar cheese

Preheat oven to 350 degrees.  Grease a 3-quart casserole or use a 13 x 9-inch baking pan.  Boil potatoes and onions together in water to cover, in large saucepan until tender.  Drain and mash.  Mix in sour cream and cream cheese.  Mix thoroughly.  Spoon into a casserole.  Whip cream and add grated cheese and mix well.  Spread over potatoes and bake for 45 minutes.  May be made one day in advance, refrigerate and cook next day.  DO NOT FREEZE.