Beat the yoghurt with the egg and water, add the oil and salt. Pour the mixture into a well in the sifted flour. Knead a smooth and elastic dough. Add a little more flour if needed. From the dough, shape 8 balls, roll them into thin wafers and anoint each with butter, sprinkle it with crumbled feta cheese and roll it.
Wrap the roll into a snail form and unroll each one flat back onto the plate, or pan. These pitas are baked on a well heated and greased hot plate, or even in a pan with a thick bottom.
The finished pitas with feta cheese are stackable after spreading butter on them.