Peel the potatoes and quarter them lengthwise. Clean, wash and cut leek into rings. Peel and finely dice carrots. Heat 3 tablespoons of oil. Fry the potatoes and carrots for about 5 minutes, turning them over.
Add the leek. Season with salt and pepper. Fry for another 10 minutes. In the meantime peel and chop the onion. Clean and wash the oyster mushrooms. Heat the remaining oil in another pan. Fry the onions and oyster mushrooms in it at medium heat for about 5 minutes. Stir the crème fraîche, mustard and 1/8 litre water into the potato pan. Bring to the boil briefly and season to taste again.
Clean and wash the oyster mushrooms. Heat the remaining oil in another pan. Fry the onions and oyster mushrooms in it at medium heat for about 5 minutes. Stir the crème fraîche, mustard and 1/8 litre water into the potato pan. Bring to the boil briefly and season to taste again. Fold in oyster mushrooms and serve
Per porton approx. 1420 kJ/ 340 kcal