Wash the meat and dab dry with kitchen paper. Clean and wash the leek and cut it into slanted rings. Wash and quarter apples, cut out the core and cut into slices.
Sprinkle with lemon juice. Heat half of the oil in a frying pan and fry the meat on each side. Then fry on each side for about 5 minutes at medium heat. Season with salt and pepper.
In the meantime, heat the remaining oil in a saucepan and lightly fry the leek and apples. Deglaze with apple juice and stock, bring to the boil and simmer at low heat for 6-8 minutes. Season to taste with salt and pepper.
In the meantime, bring milk and 150 ml water to the boil, remove from the heat and stir in the puree flakes. Let it swell for one minute, then stir again. Season to taste with salt and nutmeg. Arrange leek and apple vegetables, chicken filet and puree on two plates.
If desired, sprinkle with pepper and serve garnished with marjoram.