Begin by making the broth. In a large pot, add the meat, vegetables, and salt, and cover with water. Bring to a boil, then reduce the heat and let it simmer for about 3 hours. Once done, strain the broth and keep it warm.
While the broth is simmering, start making the cappelletti. In a large bowl, mix the flour and eggs to make the pasta dough. Knead until smooth and elastic, then cover and let it rest for about 30 minutes.
For the filling, mix the ground pork, ground beef, Mortadella, Parmigiano Reggiano, nutmeg, salt, and pepper in a bowl.
Roll out the pasta dough thinly, then cut out small circles. Place a bit of the filling in the center of each circle, then fold the dough over the filling and seal the edges. Finally, fold the semi-circle around your finger and join the two corners together to create a 'little hat' shape.
Bring the broth back to a boil, then add the cappelletti and cook for about 5 minutes, or until they rise to the surface.
