Fry the chopped onion and spinach until well softened, add salt and pepper. After cooling the mixture, add egg, mix with a spoon and add the yogurt and the feta cheese and gradually the flour mixed with baking powder. Preparation of sheet: take 3 sheets filo pastry sheets and bend along the 3 - obtained 3 rectangle, then fold them to the square and reshem them, i. e. obtained several squares. In forms for muffins put 3 square filo pastry sheets and in them in 2 tablespoons of the mixture. Protruding ends of peel mazhem with melted butter. Finished baskets put to bake in a preheated oven at 150-170C for about 15 minutes.