Mix the liver (you can order it at the butcher) with the remaining ingredients and let stand cool for about 30 minutes. If the dough is still too soft, add some breadcrumbs. Shape a small sample dumpling with damp hands or spoons and add to the boiling broth. Then turn the stove down and let the dumpling sit (approx. 20 minutes).
If the test dumpling works well, do the same with the other dumplings.