First fillet the salmon trout and place the slices with their heads in about a liter of cold water. Add vegetables, peel, spices and herbs and simmer for at least an hour. Then pass through a fine sieve. Peel and chop the carrots and celery into delicious pieces, as well as the leeks. Add to the soup and bring to a boil again until the vegetables are cooked through. Then set aside for the first time.
Knead the flour with durum wheat semolina, eggs, oil, salt, dill and match powder. Dill and matcha powder provide an attractive green color. Knead until you get a smooth dough. Wrap it in parchment paper and let it stand in the refrigerator for at least an hour.
Chop half of the fish fillet and process into a fine farce using a food processor. Add garlic, slice of toast, egg, salt and pepper. Stir as long as possible so that the mass does not become too hot. Cut the other half of the fillet into fine cubes and mix with the finely chopped dill, creamy spinach, lemon zest and crème fraîche.
Roll the dough thinly without kneading it again. You can use a rolling pin or, ideally, a pasta machine.
Put the filling in a wide strip on the pasta dough, leaving enough edge to fold into pockets later. Whisk the egg yolk and brush the edges with it. Then lightly roll the dough over the filling and roll. Use a wooden spoon with a round handle to separate the individual Maultaschen and close them with light pressure. Separate the individual Maultaschen with a knife or pastry disc.
Bring the soup to a boil again and let the dumplings simmer in boiling liquid for about eight to ten minutes. Then serve now.
Tips on buying fish sustainably can be found on the WWF and Greenpeace websites.