Knead an elastic dough from the products for it and leave it to rise. You can knead the dough in the evening, put it in a plastic bag, and leave it in the refrigerator.
In the morning, it will have risen and be ready for making buns. Make balls from the risen dough. Each is spread out, stretched slightly and smeared with beaten egg in the center, add the feta cheese and roll it into a ball.
Arrange in a baking dish, smear them with egg on top and leave them to rise.
Put a piece of butter on each bun and bake at 356°F (180 °C) until golden.