Make 2 slices per burger, of which you make the bottom with an upright edge. In it you place a slice of tomato and parmesan cheese. MozzarTblspla is also possible. Then cover the slice with the other slice and press the edges well on Tblspkaar. Sprinkle with salt and pepper and other herbs that you like. Place the burgers in a thick onion ring and fry them on the griddle on both sides. Fry the remaining onion, which you have cut into rings, gently until they are nicely translucent and golden brown. Put the hamburger in the bun and serve.