Recipe from "Biba's Italy," by Biba Caggiano
Prepare the tortelloni; In a large bowl, thoroughly combine the ricotta, Swiss chard, Parmigiano, egg, nutmeg, and salt. Cover with plastic wrap, and refrigerate until ready to use. (The filling can be prepared a day ahead.)
Cover a large tray with a clean kitchen towel and sprinkle some flour over it. Cut a thin sheet of dough into 3-inch squares. Place the filling into a pastry bag and pipe about 1 tablespoon into the center of each square. Fold the dough in half over the filling to form a triangle. Seal the dough around the filling, pressing the edges firmly together to seal. Bring the two pointed corners together and press to seal. Transfer tortelloni to prepared baking sheet. Lay in a single layer, leaving some space between them. Continue process using all of the filling and pasta. The tortelloni can be used immediately or can be refrigerated, uncovered, for several hours.
Prepare the sauce; Place the Gorgonzola, cream, and broth in a large skillet over high heat. As soon as the cream begins to bubble, reduce the heat to medium-high and cook, stirring with a wooden spoon, until the Gorgonzola is melted and the sauce has thickened, 5 to 7 minutes. Stir in parsley and season with salt. Remove from heat.
Meanwhile, bring a large pot of water to a boil over high heat. Add salt and the tortelloni and cook, stirring a few times with a wooden spoon, until the tortelloni are tender but still firm to the bite, 2 to 3 minutes.
Carefully drain the tortelloni, reserving about 1/2 cup of the cooking water, and transfer to the skillet. Stir gently over medium heat until the pasta and sauce are well combined. If the sauce is too thick, add some of the cooking water. Taste, adjust the seasoning, and serve with additional Parmigiano, if desired.