Wash the meat, dab dry and season the meat side with salt and pepper. Cut the skin crosswise with a sharp knife. Put the duck breasts with the skin side in a hot pan and fry for about 5 minutes.
Turn and fry again for about 3 minutes, then place in an ovenproof dish or on a fat pan. Add 100 ml white wine and stock and simmer gently for about 5 minutes. Roast duck breasts in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 15-18 minutes.
In the meantime, peel and core the apples, cut them into small cubes and sprinkle them with lemon juice. Stir the starch and 50 ml white wine until smooth and thicken the sauce with it. Let simmer for about 1 minute while stirring and season with salt, pepper and possibly some sugar.
Add the apple cubes to the sauce and set aside. Cook the red cabbage and cranberries in a saucepan for 8-10 minutes and season with salt and pepper if necessary. Put dumplings into boiling water and cook at medium heat for about 7 minutes.
Wash the parsley, dab dry and cut the leaves into strips. Remove the duck breasts from the oven, cover and leave to rest for 5-8 minutes. Heat butter in a pan. Remove the dumplings from the water and toss briefly in the butter.
Add parsley strips. Heat the sauce again. Cut duck breasts diagonally into slices. Arrange red cabbage, duck breast slices, dumplings and apple sauce.