Mash the feta cheese with a fork, add the eggs, olive oil and carbonated water.
Grease an oven dish with olive oil. Place 2 sheets phyllo pastry, sprinkle with stuffing, add two more sheets, stuffing, etc. Finish off with stuffing, topping the phyllo pastry generously.
Cut it into pieces. Sprinkle the top with coarsely grated cheese. Bake the phyllo pastry with cheeses in a preheated oven at 392°F (200 °C) until the cheese browns.
Remove the baked phyllo pastry and sprinkle with a little carbonated water. Wrap it in a towel for 15-20 minutes before serving.