Preheat your oven to 175°C/350°F.
Grease a 9-inch pie plate with a little oil or melted butter.
Crack the eggs into a medium-sized bowl and beat them not too hard.
Add the yogurt and baking soda. Mix until foamy.
Stir the feta cheese into the mixture.
Unroll the phyllo pastry, then paint the melted butter on one phyllo sheet.
Put two or three spoonsful of egg-and-cheese mixture on top of this phyllo sheet, leaving about 3-5 centimeters of space all around the edges.
Spread the mixture around the center of the pastry dough. Gently for this, like you are stroking the cheek of a very small, small baby, or else you will rip the dough.
Roll the sheet of phyllo pastry up loosely like a log, starting from the long side.
Beginning from the center of the pie plate, place each filled log next to each other on your pie plate. Little by little, this will form a spiral shape like a magnificent snail.
Keep doing this until you have done this with all of your pastry or you cannot fit any more pastry.
If you have left any melted butter, brush it on top of the whole pie and bake for 40 to 45 minutes, until golden.
Leave to cool for 20 minutes before you cut the pieces.
Serve with extra yogurt for the side, and also have a glass of fruit liqueur such as rakia.