The cookbook of Sabrina Welserin offers this surprisingly modern recipe to make "boiled dumplings"! which sounds delicious however, one important bit of information is missing..how do you make the dumpling dough?? Fortunately, she offers two additional recipes for dumplings, one of which refers us to "making a dough of good flour as if you would make a tart".
Then take chard, as much as you like, some sage, marjoram and rosemary, chop it together, also put grated cheese into it and beat eggs therein until you think that it is right. Take also cinnamon, cloves, pepper and raisins and put them into the dumpling batter. Let the dumplings cook, as one cooks a hard-boiled egg, then they are ready.
Let them cook beforehand in wine and strain them and take eggs, cinnamon and sugar. Bake the dough for the tart. That is made like so: take two eggs and beat them. Afterwards stir flour therein until it becomes a thick dough. Pour it on the table and work it well, until it is ready. After that take somewhat more than half the dough and roll it into a flat cake as wide as you would have your tart. Afterwards pour the plums on it and roll out after that the other crust and cut it up, however you would like it, and put it on top over the tart and press it together well and let it bake. So one makes the dough for a tart.