To boil the potatoes (skin on), start with cold water. Once tender, let them cool down a little and peel.
Mash them, add egg, salt, pepper, nutmeg and mix well.
Place the flour on the work surface and make a well in the center. Place the puree and form the dough with your hands, kneading as little as possible.
Roll into ropes and cut into small segments. If you wish, you can roll them onto a gnocchi board or a fork for a more traditional look.
Fill a large pot with water, add salt and bring to a boil. Cook them in batches. At first, they will sink to the bottom, but once they come up to the surface, they are ready. Remove with a slotted spoon.
Serve immediately with the sauce.