Bake potatoes in the oven or microwave and let cool.
On the flat top of each potato slice off a thin slice of peel and potato. Slice off most of the top peel of the potato. Scoop out most of the inside of the potatoes and place in a bowl. Leave a thin layer of potato to the shell to make sure it will hold when you put the potato back into it.
Sauté onions in butter. Add the onions, butter and cream to the potato mixture and beat until smooth. Whip the egg whites until stiff and fold into the potato mixture. Fill the potato shells. Sprinkle the top of the potato with paprika and cheese. Broil under low heat until the cheese melts.
Garnish with chopped green onion. Serve as is or with sour cream or salsa.