Peel and wash the potatoes and cook them in boiling salted water for about 20 minutes. Meanwhile wash the meat, dab dry and season with salt and pepper and cut into thirds. Heat oil in a pan. Fry the meat for about 6 minutes while turning. Meanwhile clean and wash the leek and cut it into small rings. Wash apples, cut into quarters and cut out the core. Cut quarter into slices.
Drain the potatoes and let them evaporate briefly. Warm up the milk. Add the fat to the potatoes and mash. Season with salt and nutmeg. Pour the mashed potatoes, leek, meat and apples one after the other into a greased casserole dish. Sprinkle with cheese. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes
Preparation time approx. 1 hour 10 minutes