2 sheets yufka (if you prefer to make your own, the recipe is of course also included in the book)
After washing the spinach, remove the stalks and finely chop the leaves. Then finely chop the onions and the spring onions (remove the roots and green outer layer).
Put 2 tablespoons of oil in a pan over medium heat. Add the onions and cook for 3 minutes. Add the spring onions and cook for an additional 3 minutes. Then add the spinach and cook for 3 more minutes. Mix in all the herbs and spices and set aside to cool. Grate the feta into the cooled spinach mixture.
Preheat the oven to 180ºC (350ºF/Gas 4). Whisk the milk, egg, yogurt and 2 tablespoons of oil into a mixing bowl. Unfold a sheet of yufka and slice it down the middle to create a half moon shape. Brush each half of the yufka using a quarter of the egg mixture. Spread about a quarter of the spinach mixture along the flat side of each half sheet of yufka, making a strip of about 5 cm wide. Fold the strip and tightly roll the yufka into a tube, about 80 cm long.
Brush a 20 cm wide baking tray with the remaining of the oil and place the rolled börek into circles, so that it forms a smaller ring inside the previous one. Bake for about 20 minutes or until golden. Turn off the heat and leave the tray in the oven for additional 10 minutes to rest.