Make the broth: in a large stockpot combine the Capon, Beef shank and Marrow bone with cold Water. Add a halved Onion, a peeled Carrot, a few stalks of Celery, several Black peppercorns and a generous pinch of Salt. Bring to a gentle simmer, skim any foam for the first 20–30 minutes, then simmer very gently for 3–4 hours to develop a clear, flavorful broth. Strain and keep warm.
Prepare the pasta dough: on a clean work surface mound the 00 Flour, make a well and crack in the Eggs. Add a tiny pinch of salt, beat the eggs with a fork and gradually incorporate the flour until a dough forms. Knead until smooth and elastic, about 8–10 minutes, wrap in plastic and rest for 30 minutes.
Make the filling: trim and cut the Pork loin into small pieces and finely chop or pulse in a food processor with the Prosciutto crudo and Mortadella di Bologna until a coarse paste forms. Melt a little Unsalted butter in a pan and briefly cook the mixture just to warm through (this helps concentrate flavor), then let cool.
Finish the filling: transfer the cooled meat mixture to a bowl and stir in finely grated Parmigiano Reggiano, a pinch of grated Nutmeg, a small amount of beaten egg (from the reserved Eggs if needed) and additional salt to taste. The filling should be cohesive but not wet; chill if necessary to firm it for shaping.
Roll and cut the pasta: divide the rested dough and roll thin with a pasta machine or rolling pin to about 1–2 mm thickness. Cut into roughly 4 cm squares (or rounds if you prefer). Place a small amount (about 1/2 tsp) of filling in the center of each square, fold into a triangle, seal well, then bring the two corners together and press to form the classic tortellini shape.
Cook the tortellini in broth: bring the strained, warmed broth back to a gentle simmer. Carefully drop the tortellini into the simmering broth in batches so they have room to move; cook until they float and are tender, about 2–4 minutes depending on size.
Serve: ladle hot broth and cooked tortellini into warmed bowls, finishing each serving with additional grated Parmigiano Reggiano (use more Parmigiano Reggiano for serving) and a few grindings of fresh pepper if desired. Serve immediately.
