Cut the buns into thin slices and place in a bowl. Pour the warm milk over the sliced buns and leave to soak.
Saute the onions in a pan with the butter until golden brown. Set aside to cool for a moment.
In a bowl, thoroughly knead the eggs, flour, salt, parsley, onions, and the soaked buns until combined thoroughly.
Bring a large pot of salted water to a boil.
Wet your hands (for a better grip) and form 8-10 dumplings of equal size. Carefully place them in the boiling water and simmer over low heat for about 15 minutes. You’ll know they’re ready when they float up to the surface on their own and gently rotate. They should feel firm when you remove them from the water.