Preheat the oven to 200 ° C (I only have top and bottom heat). Season the minced meat with salt and pepper and shape into 4 flat, round slices (burger patties) and fry brown on both sides.
2 Halve the bun dough pieces and distribute them on the other four so that 4 pieces are made. Roll out the dough pieces in a round shape (about 20 cm in diameter).
Cut the cucumber, tomato and onion into thin slices. Mix mayonnaise, ketchup and mustard into a sauce (add a small sip of milk if necessary) and season with salt and pepper (or to taste).
Now cover the rolled out dough in the wrong order like a burger with sauce, onion, tomatoes, cucumber, cheese, 1 minced meat patty and iceberg lettuce each, only covering the middle as the bun still has to be sealed. (In the end it is turned around in the wrong order). Of course, you can also use other ingredients, depending on your taste, just make sure that it doesn't get too much so that you can still put the roll around the filling and close it.
Now beat the dough all around over the filling so that it overlaps a little, that the rolls close well and turn over so that the "closure" is at the bottom.
Place the rolls on a tray. Mix the egg yolks with milk, brush the rolls with it and sprinkle with sesame seeds. Bake at 200 ° C for about 20-25 minutes until golden brown.