In a large bowl, combine the chestnuts, ricotta, egg, parsley, nutmeg, and salt. Blend to form a loose paste. Cut the pasta into 4-inch squares and place 1 tablespoon of filling in the center of each square. Fold into triangles, pressing out any air around the filling. Press to seal the edges. Bring the points of the long side of the triangle together, forming a ring (or a hat) and seal between your fingers.
Bring about 6 quarts of water to a boil and add about 2 tablespoons salt. Drop the tortelloni in the boiling water and cook for 8 to 10 minutes at a high simmer.
In a saute pan, heating with medium low flame, melt the butter and sage slowly, combining the flavors. Once tortelloni are done, drain pasta, reserving 1/2 cup of the pasta water. Place tortelloni in the saute pan with the melted butter and sage. Add the reserved pasta cooking water and toss to combine. Heat for about 30 seconds, seasoning with salt and freshly ground black pepper to taste. Serve.
Mound 3 1/2 cups of the flour in the center of a large wooden cutting board. Make a well in the middle of the flour and add the eggs and the olive oil. Using a fork, beat together the eggs and oil and begin to incorporate the flour, starting with the inner rim of the well.
As you expand the well, keep pushing the flour up from the base of the mound to retain the well shape. The dough will come together when half of the flour is incorporated.
Start kneading the dough with both hands, using the palms of your hands. Once you have a cohesive mass, remove the dough from the board and scrape up and discard any leftover bits. Lightly re-flour the board and continue kneading for 6 more minutes. The dough should be elastic and a little sticky. Wrap the dough in plastic and allow to rest for 30 minutes at room temperature. Roll or shape as desired.
Recipe copyright 2001, Mario Batali. All Rights Reserved.