Clean, wash and chop the leek. Fry the ham in hot oil. Fry the leek for about 5 minutes. Season with pepper. Stir in half sour cream and cheese. Roll out the dough, quarter it and leave it on the paper.
Preheat oven (electric cooker: 225 °C/circulating air: 200 °C/gas: see manufacturer).
Spread the leek mixture on one half of each dough piece. Fold the other half over, press down the edges. Sprinkle with the rest of the cheese. Bake in the oven for 15-18 minutes. Serve and add the rest of the sour cream.