Wash well and mince the spinach. Add 1 tbsp salt and rub the spinach with your hands. Leave it with the salt for 1 hr and strain it well. Add 1/3 cup olive oil, onions, leeks, feta in small bits (if not ground), eggs, dill, salt, (be careful in case the feta cheese is salty) and pepper. Prepare the pie according to the instructions and bake in a preheated oven for 40-55 min. Leave is aside to cool down and cut it.

To form the pie in a rectangular baking pan:
Smear the inside and sides of the baking pan with olive oil. Open the sheets and lay half the sheets, smearing them in between with olive oil.
Pour the stuffing on top, leaving the inside sheets to exceed from the baking pan, and cover with the remaining sheets, also smearing them in between with olive oil.
Fold the exceeding edges of the sheets all around, slightly twisting them. Carve the surface in portions, beat 1 egg and smear with it the last sheet.