Cut the bacon into cubes and leave them crisp in a pan without fat. Wash parsley, shake dry, pluck leaves from the stalks and chop them except for something to garnish.
Cut the rolls into small cubes. Pour 250 ml milk over them and soak for about 5 minutes. Add eggs, bacon and parsley and knead. Season with salt and pepper and knead well again.
Form 8 dumplings and let them simmer in boiling salt water for 10-15 minutes. Clean and wash the leek and cut into fine rings. Wash the meat, dab dry and season with salt. Heat the oil and fry the meat for about 4 minutes while turning.
Melt the fat in a pot. Stir in flour and sweat briefly. Add white wine, stock and 100 ml milk while stirring. Bring to the boil, boil for 3-5 minutes and season with salt and pepper. Cut cheese into cubes.
Add 2/3 of the cheese to the sauce and dissolve while stirring. Stir in the leek. Cut dumplings into slices. Put meat and dumplings into a greased casserole dish. Spread the sauce over it and sprinkle with the rest of the cheese.
Bake in the preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: stage 1) for approx. 15 minutes. Garnish with parsley.