Wash, peel and dice the potatoes. Peel onion and also dice. Heat 15 g fat in a pot, fry the onion until transparent. Add potatoes, dust with curry and braise while stirring. Deglaze with stock, bring to the boil, cover and cook for 12-15 minutes. In the last 5 minutes add lentils and bring to the boil. In the meantime clean, wash and cut leek into fine rings.
Heat the remaining fat in a coated pan and steam the leek for about 2 minutes. Put it on a plate. Cut the sheep's cheese into slices and turn briefly in flour. Heat the oil in a frying pan and fry the sheep's cheese until golden brown while turning. Season the potato and lentil curry with salt and possibly some curry and put it in a bowl. Put sour cream as a blob on top, sprinkle with leek and arrange the feta cheese on top. Serve garnished with parsley