For the filling, clean and cut the leek. Fry together with the minced meat in a pan. Then deglaze with the milk and season with salt, pepper and a little marjoram, finish cooking.
Cut the stale bun into small cubes and toast in the small pan with the butter. Let everything cool down. Then fold the cold buns into the minced meat.
Shape the dumpling into 6 dumplings and fill them with the minced meat mixture. In the Saarland the dumplings are kept so big (Kindskäbb big) that one is full of one dumpling alone.
Put in boiling salted water and cook on a mild heat - the water should move slightly - for about 1/2 hour.
For the sauce, dice the streaky bacon and leave it in a pan. Deglaze with the cream and add a little salt to taste.