Crush the feta cheese in a bowl and mix it with the chopped into small cubes butter, then add the 2 tablespoons sour cream. In another bowl, mix the yoghurt and eggs and 2 tablespoons of sour cream.
Sprinkle each phyllo pastry sheet with a little butter and the mixture of cream and feta cheese and arrange the sheets in the shape of a hand fan, taking care to have the feta cheese fall into the folds.
Arrange them in a tray greased with half the oil, starting from one end and packing tightly toward the other end of the tray. Repeat this process with all of the sheets until finished. Top the pleated pastry with the egg mixture and gently shake the tray to have some of the mixture fall in between each fold.
Pour in the remaining oil or add pats of butter and bake in a preheated 392°F (200 °C) oven until golden.