Minced meat is mixed with chopped onions and seasoned with salt and pepper. 8 are formed flat meatballs are sprayed with water and four of them rank in the tray, the bottom of which is covered with parchment paper. Top covered with another sheet of paper and kept in the oven 3 minutes at 600 Deut. Remove, turn around, as these parts were inward oriented outwards, and kept another 3 minutes at 600 Deut. Stay in the oven for 2 minutes at off oven. Similarly were prepared and the remaining 4 meatballs. Rolls are cut, optional can toast and place in them 1 lettuce leaf, 1 meatball and tomato slice.