Put the flour in a bowl, put the yeast in the middle and sprinkle the sugar over it. Warm the milk slightly, stir with the yeast and let it steep for about 10 minutes. Add the butter and egg yolks. Knead everything well and let rise for 30 minutes.
For the topping: Dice the onions and sauté lightly. Add the minced meat and stew for 3 - 4 minutes. Pour in the tomatoes and mash them. Season heartily with paprika, ketchup, salt and pepper. To let it cool down.
Knead the yeast dough well again and place in a tart pan. Brush with the cooled minced meat mixture. Bake at 180 degrees for 20 minutes. Then sprinkle the cheese on it and leave it in the oven for another 5 - 10 minutes.