Crumble the feta cheese in a bowl, add 4 eggs, the baking soda and yoghurt and stir.
Melt the butter, take 3 sheets at a time, smear each with butter and place on top of each other. Sprinkle evenly with the filling and roll up into a roll, starting from the wide part.
Repeat with the rest of the sheets and filling. Oil a round tray and arrange the rolls in it in a spiral, starting from the middle.
Make a topping from the milk beaten with the remaining 2 eggs and pour it over the phyllo pastry, distributing it evenly.
Bake at 338°F (170 °C) about 40 min. until golden.