Cut the bacon and onions into small cubes, mix with the chopped chives and pepper, form 8 balls out of the mixture and refrigerate them.
Boil the potatoes, peel them and press them through the potato press while they are still hot. Add semolina, 1 egg, butter, salt and cornstarch and quickly knead everything into a dough with your hands. Shape it into a roll and divide it into 8 equal pieces. Press the pieces of dough flat with floured hands, place a bacon ball on each, seal the dough over it and form round dumplings.
Whisk the milk with 4 eggs and a pinch of salt well.
Place the dumplings in a greased pan, carefully pour the milk and egg sauce on the side (not over the dumplings) and put the pan in the oven at 180 ° C for about 1 hour until the dumplings have a nice brown surface.