Tortellini are not dumplings. They are not ravioli. They are not meant to be drowned in cream or tossed with butter. They are small, precise packages of filling wrapped in the thinnest possible sfoglia, shaped with a movement so particular that Bolognese grandmothers can tell by watching your hands whether you learned properly.

The filling is not negotiable. Pork loin, prosciutto, mortadella, Parmigiano-Reggiano, egg, and nutmeg. Each ingredient in proportion. The mortadella provides fat and its distinctive perfume of pistachios and spice. The prosciutto gives salt and depth. The pork loin adds sweetness. The Parmigiano binds everything and brings its crystalline sharpness. If you change the filling, you have made something else. Call it what you like, but do not call it tortellini.

The shape comes from legend: a innkeeper peering through a keyhole at Venus, seeing only her navel, and recreating what he saw in pasta. Whether the story is true matters less than what it tells you about how Bolognesi feel about their tortellini. This is not just food. This is identity.

In Bologna, on Christmas Day, you serve tortellini in brodo. Golden capon broth, clear and rich, with small tortellini floating like treasures. That is the dish. Cream is an insult. Tomato sauce is incomprehensible. What you keep out is as significant as what you put in.