Grate the cheese. Knead 350 g flour, 200 g butter in pieces, lemon juice, crème fraîche and cheese in a bowl. Wrap in foil and chill for about 1 hour.
In the meantime clean and wash the leek and cut it into fine rings. Peel, wash and chop the carrots. Heat the oil in a large pan bit by bit. Fry the chopped leek in 2 portions for 4-5 minutes while turning.
Take it out. Add leek and carrots to the pan and fry for about 3 minutes. Add the minced meat again. Add ketchup and 1⁄4 l water, stir in broth, bring to the boil and simmer at medium heat for 10-12 minutes (liquid should be almost overcooked).
Season to taste with salt and pepper.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease a muffin tray (12 troughs) well. Roll out the dough on a floured work surface to a thickness of approx. 1⁄2 cm and cut out 24 circles (12 circles of 11 cm Ø + 12 circles of 9 cm Ø).
Place the large circles in the troughs of the muffin tray. Spread the chopping mixture inside. Place the smaller circles on top and press the edges of the pastry together with a fork. Coat the tops of the pastry with egg yolk.
Bake in a hot oven for 35-40 minutes. Remove. The pies taste hot and cold.