Preheat oven to 425 degrees F. Beat an egg white in a shallow bowl. Put sea salt or kosher salt in another shallow bowl or plate. Wash and dry 4 russet/baking potatoes. Prick all over with a fork. Roll in beaten egg white and then in salt until well-coated. Bake on the rack in the middle of the oven for 1 hour. Serve with butter and/or sour cream, and freshly ground black pepper to taste…. or any other topping you’d like.