Place potatoes in a large heavy saucepan and cover by 1 inch with cold water. Bring to a boil over high heat and cook until the potatoes are tender to the tines of a fork, 15-20 minutes. Drain in a colander and let cool slightly.

When they are cool enough to handle, peel the potatoes and rice or mash them, taking care to not leave any large pieces or chunks. Turn them out onto a lightly floured surface, shape into a mound, and let cool slightly so they are still warm but can be kneaded by hand.

Make a well in the center of the potatoes and pour in the eggs. Add the flour to the well, then add the cheese and season with the nutmeg, 2 teaspoons of salt, and a few grinds of pepper. Knead the mixture with a fork and then by hand, just until the ingredients are seamlessly integrated and come together in a dough.

Dust your hands with flour, and if necessary, reflour the work surface. Divide the dough into 6 pieces. Working with one piece at a time, roll it out into a rope about ½ inch in diameter. Use a sharp knife to cut each rope into 1 inch segments and transfer to a rice-flour-dusted baking sheet.

The gnocchi can be refrigerated for up to 1 day or frozen for up to 2 months.

Fill a medium pot 2/3 full will water and salt it liberally. Bring to a boil over high heat. Add the peas and cook just until they turn bright green, about 30 seconds, then immediately drain in a colander and rinse under cold water to stop the cooking and preserve their color. Set aside.

Fill a large pot about 2/3 full with water and salt it liberally. Bring to a boil over high heat.

Meanwhile, heat a large heavy sauté pan over medium-high heat. Add 1 tablespoon of the butter and let it melt, coating the pan. Add the prosciutto and cook, stirring with a wooden spoon, just to warm and infuse the butter with its flavor, about 1 minute. Stir in the cream and bring to a simmer, then lower the heat and simmer gently until it redues and thickens enough to coat the back of the spoon, about 5 minutes.

When the water comes to a boil, add the pasta and cook until al dente, about 2 minutes for fresh or 7 minutes for dried.

Meanwhile, stir the peas and remaining tablespoon of butter into the sauce, letting the butter melt. Drain the pasta and add it to the sauté pan. Toss to coat with the sauce, then stir in ½ cup of the cheese to melt and thicken the sauce.

Divide the pasta among individual plates, finishing with a few grinds of black pepper, a sprinkling of cheese and arugula.