Prepare a yeast dough from the first five ingredients and leave to rise covered in a warm place.
As soon as the amount of dough has doubled, lightly grease a drip pan with margarine, line it up with the dough and let it rise again.
In the meantime, clean the leek stalks, cut them into rings and pull them apart relatively well so that individual rings are created as possible. Then cover the dough with the pizza tomatoes and sprinkle fresh or dried herbs on top. Sprinkle some grated cheese on top and season well with salt, pepper etc. as required.
Mix the sour cream from the mug with the egg yolk and a little milk so that it becomes softer and can be dabbed on the tomatoes. Now pour the leek rings over the entire mixture and sprinkle vigorously with grated gratin cheese. Finally, grate or slice some parmesan and sprinkle over it.