Boil the potatoes in their skins in salted water and peel them whilst they are still warm. Pass them immediately through a vegetable mill (mouli-légume). You should have
Add the egg, flour, and salt and pepper and work in well. Take pieces of the potato mixture and roll into thumb-thick rolls, then cut into short pieces
Boil the gnocchi in plenty of salted boiling water and as soon as they rise to the surface, remove them with a perforated spoon.
Serve gnocchi with tomato sauce, with shredded basil added to taste and freshly grated Parmesan cheese.
The potatoes can be cooked in their skins in a plain or convection microwave; it is really better than the boiling method.