Boil the potatoes in the skin for about 20 minutes, drain, let cool and peel. Wash the fillet, pat it dry, remove it from the bone and carefully peel off some of the skin from one side with a sharp knife. Peel and core the apples and cut into wedges. Pluck the rosemary needles from the stems, push the herbs under the skin and fix the skin with toothpicks. Wash and drain the sprouts.
Heat the oil in a pan, sear the meat in it vigorously and fry over low heat for about 8 minutes per side.
Season with salt and pepper, remove and keep warm.
Cut the potatoes into quarters, fry them in the frying fat, turning, and add the rosemary. Briefly fry the apple slices (reserve some for decoration), add stock and Asian sauce, bring to the boil, season with salt and pepper and mix in the sprouts.
Arrange 1 chicken fillet with potato-apple mix on each plate. Garnish with plucked marjoram and apple slices as desired.