Rinse the spinach well and chop it finely. Add tablespoon of salt and rub the spinach with your hands. Leave it in salt for an hour and then drain it well. Add 1/3 cup olive oil, fresh onions, feta cheese in small pieces, eggs, dill and parsley, salt and pepper.
In a buttered baking pan (size 10x14x2) roll out the crust flaky pastry. Baste it with olive oil. Then spread the spinach mixture and cover it with 6 crust flaky pastries basting each one with olive oil. With a knife cut the last 3 flaky pastries in squares of six centimeters.
Sprinkle some water on it to prevent flaky pastries from folding. Bake spanakopita in medium temperature for 40-45 minutes.
Let it cool and then cut it in square pieces. Serve it hot or cold.
This recipe is for about 20 pieces.