Sift the flour. Add 4 eggs, the water, salt and baking soda. Knead a soft dough. Divide it into 4 balls and leave them to relax for a little bit.
Roll out each ball into a thin sheet. Put a large quantity of water in a pot to come to a boil on the stove. Put the 1st sheet in it for 2-3 min., then take it out and dip it in icy-cold water.
Place the ready sheet onto a clean towel. Do this for all of the other sheets.
Smear the bottom of a suitable oven dish with melted butter. Place the 1st sheet in it. Smear it with butter on top and place the 2nd sheet. Sprinkle generously with grated feta cheese and cheese. Sprinkle with butter.
Repeat this process for the rest of the sheets. Cut them into squares. Pour on the mixture of 2 beaten eggs and melted butter.
Put it in the oven and bake for 20 min. at 356°F (180 °C). Take the oven dish out, sprinkle with grated cheese and bake until golden at 428°F (220 °C).