Cut the rolls into small cubes. Warm the milk, pour it over the roll cubes and soak for about 30 minutes.
Cook the pasta in plenty of boiling salted water for about 12 minutes until al dente
Add onion, chives, eggs and cheese to the rolls. Knead everything well and season with 1 tsp salt and 1⁄2 tsp pepper. If the dough is very soft, knead in some breadcrumbs. Cover the dough and let it rest for about 30 minutes.
Form 12 dumplings from the dough with moistened hands, pressing the dough firmly together. Bring plenty of salted water to the boil in a large saucepan. Add the dumplings to the boiling water and let them simmer at low to medium heat for 15-20 minutes. When the dumplings float to the surface, lift them out with a skimmer.
Bring the stock to the boil, season to taste. Arrange dumplings in soup bowls with hot stock. Sprinkle with chives if necessary.