Transfer the
puff pastry dough to a pastry bag fitted with a five-eighth inch plain tip. Hold the dough-filled pastry bag at the edge of the pot with the tip over the boiling water. Working very rapidly and using a small knife, cut off 1" long sections of dough so they drop into the water.
Cook the dumplings until they puff, about 3 minutes. Drain the dumplings well with a skimmer and
place immediately into the
gratin dish.