Wash the potatoes and cook in boiling water for about 20 minutes. Drain, rinse and rinse thoroughly with water immediately. Peel the potatoes and press them through a potato ricer. Knead in 75 g flour and egg yolk.
Season with salt and nutmeg. Pour the mixture into a piping bag and spray an approx. 30 cm long roll onto a floured work surface. Cut it into pieces of about 5 cm length. Repeat the process until the mixture is used up.
Whisk the eggs in a deep dish. Turn the potato rolls first in 6 tablespoons of flour, then in the egg and finally in breadcrumbs. Clean and wash the savoy cabbage and cut it into strips from the stalk. Wash duck breasts, pat dry and cut the skin with a sharp knife in a diamond shape.
Season with salt and pepper. In an ovenproof pan or flat roasting pan, first fry on the skin side for approx. 3 minutes until crispy, then fry on the meat side for approx. 3 minutes. Continue to cook in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-12 minutes.
Melt 1 tablespoon of butter, add the savoy cabbage and stew for 5 minutes. Season to taste with salt and pepper. Take duck breasts out of the oven, wrap them in aluminium foil and let them rest. Drain the cooking fat. Dissolve roasting fat with red wine, bring to the boil and add stock.
Season to taste with salt and pepper. Knead 30 g butter with 25 g flour, stir slowly into the sauce and simmer for 1-2 minutes. Add the cranberries. Meanwhile bake croquettes in hot oil in portions until golden brown.
Cut duck breasts into slices and arrange on plates with croquettes, savoy cabbage and cranberry-red wine sauce.