# Firstly, prepare the dough. Break the egg into the mixing bowl, add water,
milk, sunflower oil and vinegar on it. Add salt and
flour, until the mixture stops to sticking to your hands and reach medium consistency, into the mixture and knead it.
# Cover the dough and rest it for about 20-25 minutes. Meanwhile prepare the filling. Chop the white and the green parts of the
leeks finely. Put 3 tbsp vegetable oil into a small pot. Add
leek pieces on it. Cover the lid of the pot, and cook it over low heat for about 20 -25 minutes.
# When the cooked
leek pieces cool down a little, add mashed
cheese,
yogurt,
tomato paste and salt in it and mix it a little. Put it aside.
# Divide the rested dough into 24 pieces. Roll out each of the pieces into the size of dessert plate. Spread melted margarine between each of them, while placing 4 of the pieces over and over. You will get 6 groups by this way.
# Rest the dough groups in the freezer to make the oil between the layers solidify. Then, roll out first dough group over the bench, starch and
flour sprinkled, a little bit bigger than oven tray size. Place it into the greased baking tray by gathering a little.
# Pour about 2-3 tbsp melted margarine all over. Roll out the second group of dough by the same way and spread melted margarine all over also. Place the third part of the dough into the tray also by the same method, and then place the mixture of
leek over it.
# Roll out the remaining dough pieces also by the same way, then place them over the
leek layer in the tray. Spread the remaining margarine all over, slice the borek into square shaped pieces.
# Place the tray into the oven which is preheated to 383 F, and bake until it turns into red.
# Rest it for 20 minutes, after removing it from the oven. You can serve it.