Potato Gnocchi

Method

1. Pierce the russet potatoes several times with a fork and bake them directly on the oven rack at 400 degrees F (200 degrees C) until a skewer meets no resistance, about 1 hour. Baking rather than boiling keeps them dry, which means less flour later.
2. Split the potatoes as soon as you can handle them and press the flesh through a ricer onto a work surface. Spread it out and let the steam escape for 5 minutes; trapped moisture makes gummy gnocchi.
3. Sprinkle the salt and ground nutmeg over the potato, drizzle on the beaten egg, and scatter 1 1/4 cups of the all-purpose flour over the top. Fold and press with a bench scraper just until a soft dough forms, adding more of the remaining flour only if it sticks badly.
4. Roll pieces of dough into ropes 3/4 inch (1.9 cm) thick on a lightly floured board and cut them into 3/4-inch (1.9 cm) pillows. Roll each down the tines of a fork if you want ridges, and keep them dusted so they do not stick.
5. Drop the gnocchi into a large pot of well-salted boiling water in batches. They are done about 30 seconds after they bob to the surface, roughly 2 minutes total.
6. Melt the butter in a wide skillet over medium heat with the sage leaves and cook until the butter smells nutty and the leaves crisp, about 3 minutes. Add the drained gnocchi with a spoonful of the cooking water, swirl to coat, and finish with the Parmesan cheese.