In order to remove all traces of milk, put the udder into lukewarm water and let soak for 2 to 4 hours, permitting the water to cool off. Then cook the udder in a 2-percent to 3- percent salt water solution until tender. Remove from the cooking liquid and cut into 1/2-inch thick slices. Let the slices dry a bit. Season on both sides, dip into whisked egg, and then into breadcrumbs. Fry in butter, turning once, until golden brown on both sides.