In Rome, the pasta course is called the primo and is modest, because something else is coming after, so this amount serves 4. We often have this alone, in which case it serves two adults and a child generously. If you double up, cook in two, even three batches.
Serves 4 as a starter
600g floury potatoes (eg russet)
300g plain flour (you probably won’t need all of this)
1- 2 eggs (optional)
1 Scrub but don’t peel the potatoes, boil them whole in salted water until tender. Drain, then put the empty pan back on a low heat until it is dry, add the potatoes and let them dry for a moment, too. Once the potatoes are cool enough to handle, peel them, then pass them through a potato ricer into a bowl, or mash them with a fork. You can also do this with the grating attachment of a food processor. If you are going to add an egg, do it now and mix well.
2 Turn the mixture out on to a floured work surface, add flour to the potato and work it in. Continue adding flour and kneading until you have a consistent dough that no longer sticks to your hands. The amount of flour will vary; the most important thing is the feel of the dough.
3 Dust the work surface with flour, pull off an egg-size lump, roll it into a 2cm-thick rope, then cut the rope into 1cm pieces. At this point, if you want you can make the distinctive grooves with a gnocchi board or by pressing the gnocchi gently on a cheese grater or the back of a fork. Lay the gnocchi on a clean tea towel.
4 Bring a large pan of water to the boil, add salt, stir, then gather up the tea towel so as to gently drop all the gnocchi in at once. Once they bob to the surface, scoop them out with a slotted spoon. Have a warm serving plate and the sauce ready, so when the gnocchi are cooked, you put them straight on the plate, top with the sauce and serve.