Add butter, milk, salt to potatoes. Mix well. Cool. Add enough flour to form a non.sticky dough. Add flour gradually, the less the better. Divide into 24 pieces. Roll each piece out, using flour to keep from sticking. Heat a griddle or frying pan over medium heat. Lightly grease with salad oil. Place on grill. Lefse will bubble, turn over. (Approx. 2 min).