Yeast, fuzzy bit of lukewarm water mixed with a little flour and is allowed to rise. Add half of the oil, egg, remaining flour, salt and lukewarm water. Blended into a medium soft dough, which is left to rise. During this time the leeks cut into medium-sized pieces and stew in remaining oil until soft. Then it is to add the grated feta cheese. The risen dough is divided into two halves. One half is spread on the bottom of a greased baking dish with butter and cover with a mixture of leeks and the feta cheese. Top rank tomatoes, cut into rings (can tomato paste), and cover with the second half of the dough stretched sheet. Cake bake in a moderate oven.