Peel the potatoes and boil in lightly salted water for about ten minutes, they should still be very firm in the center, chop coarsely. Mix all the ingredients in a large bowl with your hands and run through a grinder with a sausage stuffer attachment.Tie off the stuffed casings with two knots at 12 inch intervals and sever in between. A 12 inch length of korv is equivalent to one standard serving. Fill a pot large enough to comfortably hold the the number of rings you wish to cook with water and bring to a boil.Add the rings of korv and boil for 45 minutes. Prick the sausage skins as they boil to release the entrapped air. The proper accompaniment to hot korv is boiled potates, green peas and copious amount of butter.