Cut the pork in small dice. In a saucepan on medium heat place the butter. When the butter starts foaming add the diced meat. Sauté and cook the meat until lightly browned. Transfer the meat to a food processor. Pulse a few times to reduce to a coarse compound. Add the mortadella and prosciutto to the processor. Run the blade until all the meat is very finely ground. Transfer the ground meat to a shallow bowl. Add the egg, the freshly grated nutmeg, and the grated parmigiano reggiano. Combine all ingredients very thoroughly together. Prepare pasta dough using my pasta dough recipe. Make the dough very soft, using just enough flour to avoid the dough sticking to the hands while working. Flatten the dough with the rolling pin or machine. Divide the dough in several pieces. Place one piece on the work surface and set the rest aside. Cover the reserved dough with plastic wrap to prevent it from drying. Using a round fluted pastry cutter, cut the dough in rounds. Place approximately half tablespoon of the filling in the center of each round. Fold the round in half in a half-moon shape. The recipe will make approximately 300 cappelletti, enough for 6 to 8 people. Place approximately 1-½ quart (1500 cc) of the broth to a boil. When the broth is at a fast boil drop the tortellini.Cook the cappelletti until “al dente” (firm but not too soft or overcooked.) Cooking time may vary depending on the freshness of the cappelletti. Dried cappelletti may take a little longer then freshly made cappelletti. Place the cappelletti in serving bowls, top with freshly grated parmigiano reggiano cheese, and optionally, with freshly grated nutmeg.