Preheat oven to 350 degrees F.
Pare the potatoes and boil thirty minutes. Drain the water from them, and mash very fine; then mix thoroughly with the fish.
In a small saucepan, scald the milk or cream. Then add this, butter, salt, and pepper to the potato mixture.
Let mixture cool while you beat the two whole eggs. Add to potato mixture, spread in a 13 x 9 inch baking dish, and bake for 10 minutes.
Separate the last two eggs, setting aside the yolks. Beat the yolks. In a very clean bowl, beat the egg whites to a stiff peak, then fold in 1/4 teaspoon salt and the yolks.
Remove baking dish from oven, spread egg white mixture over the top, then return to the oven to brown. Serve.
