Grease a tray. Beat the eggs with a pinch of salt, add the yoghurt, crumbled feta cheese and stir.
Stack the ready-made phyllo pastry sheets, sprinkle a little oil between each, and between every 2-3 - put filling. Finish off with 2 phyllo pastry sheets and spray with oil.
Bake in moderate oven at 338°F (170 °C) until golden.