Place the butter in a frying pan and fry the pork and chicken until golden and the inside temperature is at least 165 degrees F.
Using a meat grinder, grind the pork, chicken, mortadella and prosciutto. Grind fine. If a meat grinder is not available use a food procesor and finely process to a finely chopped mixture.
Add the Parmigiano-Reggiano, egg and nutmeg. Mix well.
The dough will be rolled into 2-3 inch squares (can be rounds).
Place a square on a clean flat surface. Wet the edges of the square.
Use 1+ tsp of the filling onto the square. Fold over the square and seal and fold into the tortillini shape.
The tortillini are not pre-coopked, but rather dropped into boiling broth. They will cook in abot 8-10 minutes.