Preheat oven to 375 degrees. Cut potatoes into large cubes. Boil in salted boiling water until tender. Drain well, and put through a ricer. Mix well and combine with butter, egg yolks, salt, pepper, and nutmeg. Mixture should be thick.
Spoon the potato mixture into a pastry bag fitted with a -inch sawtooth tip. Pipe potato mixture into small mounds onto a buttered baking sheet.
Bake 8 to 10 minutes, or until golden brown.
Variations:
MASAGRANS:
Shape potato duchess into patty shells. Bake
POTATO GALETTES:
Shape potato duchess in 2 to 3-inch rounds cakes, or into rectangular shapes.
POTATO MARQUISE:
Potato duchess mixed with tomato paste and paprika.
BERNY POTATOES:
Add to duchess potato, chopped truffles, and sliced almonds