Wash and clean the spinach thoroughly until you have 2.2 lbs (1 kg) cleaned spinach.

In a large deep skillet, heat 5 tablespoons olive oil and sauté the onion for a few minutes. Add the spinach and dill, and cook until wilted.

Transfer the spinach mixture to a colander set over a bowl and let it drain. Press the spinach with a wooden spoon to remove as much liquid as possible.

In a large bowl, add the sifted flour and make a well in the center. Add the olive oil, vinegar, salt, and gradually add the water while kneading. When the dough no longer sticks to your hands, divide it into 4 balls and set aside for a while.

On a clean surface, sprinkle a little flour and roll out each dough ball with a rolling pin. Flip and dust with more flour as needed to prevent sticking. Repeat this process 3-4 times for each ball.

Grease a baking pan well and lay down the first sheet of dough. Brush lightly with oil and add the second sheet.

In a bowl, combine the spinach, salt, pepper, feta, and egg. Mix well with a wooden spoon.

Once cooled, spread the filling evenly over the dough in the pan.

Roll out the remaining two sheets of dough and place them over the filling. Pinch the edges of the dough together to seal the pie.

Brush the top sheet with oil and sprinkle with sesame seeds. Score the top of the pie without cutting all the way through.

Bake in a preheated oven at 350°F (180°C) on the middle rack for 50-60 minutes.

Remove from the oven, let cool for 15 minutes, and serve.