How to Make It
Cook the potatoes in boiling salted water until tender, about 15 minutes. Drain, then press through a large fine strainer into a bowl. Let cool slightly, then beat in the flour and eggs.
In a small saucepan, bring the cream and milk to a simmer. Add to the potatoes and whisk until smooth. Season with the salt and white pepper. Beat the egg whites until firm, then fold them into the potato batter.
Heat 1/2 tablespoon of the oil in a large nonstick skillet. Spoon 3 tablespoons of the batter into the skillet for each pancake and cook over moderate heat until golden on the bottom and barely dry on top, about 2 minutes. Flip the pancakes and cook until golden, about 2 minutes longer. Add some more of the oil for each batch. Serve hot.