Wash the potatoes and cut them into a few large chunks. Boil them in lightly salted water until they are tender; about 10-15 minutes. Remove the skins and mash them or put them through a ricer into a large bowl. Set aside. Heat the olive oil in a skillet over medium heat and add the garlic. Stir for about 30 seconds, then add the onions. Remove from heat and add to the potatoes. Add the ham, parsley, nutmeg, pepper and eggs and mix. Place the flour on one plate, the beaten egg on another, and the bread crumbs on a third. Scoop up small amounts of Prosciutto di Modena PDO and potato mixture and form into small cylinders. Roll each one in the flour, then egg, then the bread crumbs. Fry the croquettes in small batches in a heavy skillet heated to about 375°F. until they are browned on all sides.