Cut the pasta into 5-centimeter (2-inch) squares with a roller cutter or knife (use a ruler to notch the dough in order to make regular cuts).
Pipe ¾ teaspoon of filling in the center of each square. Moisten the edges of the pasta with water to help them seal.
Fold the squares into triangles, press out any air around the filling, and press to seal the edges.
Dab the points of the long sides with water, then bring them together to form a ring, and seal them between your fingers.
Set the tortellini aside on a sheet pan lined with parchment and sprinkled with semolina or cornmeal, cover well with plastic wrap, and refrigerate until ready to cook.