Peel the potatoes and cut into small pieces. Boil in salted water, add some nutmeg at this point. Pouring off.
Beat in the food processor with a little milk, cream, salt, pepper and a lot of nutmeg until frothy. This increases the volume by about half. Just before serving, stir in a few flakes of butter.
This potato foam is much more fluffy than mashed potatoes or mashed potatoes. With a little more milk you get a great potato soup (also the next day to use leftovers).