Potato Timbale a la Parmentier

Remove some rounds with a three-quarter inch diameter tin tube from slices of potatoes three-sixteenths of an inch thick; saute them in butter for two minutes, then drain. Line the bottom of a buttered timbale mold with part of these rounds, and the sides with separate rows laid on flat, intercalating them in such a way that a round of potato lays between two others of the next row. Prepare a puree with a pound of potatoes boiled in salted water, drained and covered with a damp cloth, then dried in the oven; rub through a sieve and stir in two ounces of butter, one whole egg, one yolk, salt and nutmeg. Fill the timbale with this, lay the cover over and push into a moderate oven to cook for half an hour or more; when removed let stand for ten minutes, and invert on a hot dish.