This is a Christmas dish more than anything else on this menu, and we make an exception to open on the one Sunday a year it falls on, because Christmas without this in front of you is not really Christmas in this family, restaurant open or not.
Serves 6–8.
Finely chop or process the prosciutto, mortadella, and pork loin together until you have a fine, even paste rather than distinct pieces. Mix in the Parmigiano, egg, nutmeg, and a pinch of salt, and chill the filling for at least thirty minutes -- a cold filling is far easier to work with than a warm one.
Make the pasta dough by mounding the flour, forming a well in the center, and working in the eggs gradually until you have a smooth, firm dough. Knead for eight to ten minutes, then rest it, wrapped, for thirty minutes.
Roll the dough as thin as you can manage, and cut it into small squares, about four centimeters on a side. Place a small dab of filling in the center of each. Fold each square into a triangle, pressing the edges firmly to seal, then wrap the triangle around your fingertip, bringing the two bottom corners together and pinching them to join, and folding the top point back slightly. This is the shape the dish is named for, and it takes longer to describe than to actually do, once your hands learn it.
Bring the broth to a gentle simmer -- not a rolling boil, which will tear delicate tortellini apart. Cook the tortellini directly in the broth, in batches if needed, for two to three minutes, until they float and the pasta is tender. Serve immediately, in the broth itself, with Parmigiano at the table.
If the tortellini fall apart in the broth, either they weren't sealed firmly enough, or the broth was at a hard boil instead of a gentle simmer; lower the heat, and press the edges more firmly next time. If the filling leaks out during cooking, the dough was rolled too thick to seal properly around it, or too much filling was used for the size of the square. And if the broth tastes thin despite everything else being right, it was under-seasoned or under-reduced to begin with -- in this dish, the broth is not a background element, it's half the meal, and it needs to taste like it.
A man has come in on the same date every single year for longer than most of our current staff have worked here, always alone, always asking for the same corner table, always ordering tortellini in brodo without needing to look at the menu. It was his late wife's favorite dish, and the date is their anniversary. Nobody on staff needed to be told this more than once for it to simply become how things are done here.
That table isn't offered to anyone else on that particular date, every year, without a single word ever having been exchanged about it among the staff. Salvatore says it isn't a rule, exactly. It's just what the restaurant does now, the way water finds the same path down a hill twice.