When perfectly cold slice rather thin. Put into a pan.
Sprinkle on a little flour and toss the potatoes about with your hand until some flour adheres to each piece.
Cover these floured potatoes with small bits of butter. If the butter is put in in one piece the potatoes get broken before the butter reaches them all.
Sprinkle in a little salt and put in enough cream so that they are about half covered. If you use more cream they will cook too tender and be mushy before the cream is cooked down. Stand by them. Stir with a knife blade lifting them from the bottom but not turning them over.
When they begin to glisten lift them to a hot serving dish and put them where they will keep warm but will not cook any further.
Notes
If you have not cream add a little more butter but the cream is better than the butter.