Process all the dough ingredients into a smooth dough. Then wrap in cling film and let rest in the refrigerator for 30 minutes.
For the filling, cut the mozzarella, ham and salami into pieces of any size, season the tomatoes and mix everything together. Roll out the dough and cut out circles with a cup. Place some of the filling in the center of the circles, coat the edges of the pastry with egg white and fold up. Brush the dumplings with egg yolk, place on a baking sheet lined with baking paper and bake for 20 minutes at 220 ° C until golden.