First, make the topping: beat the eggs, add the milk. Stir, pour in the carbonated water and oil. Stir again and leave aside.
Separate out the phyllo pastry sheets. Place 1 sheet on a counter, sprinkle with crumbled feta cheese and fold it up like an accordion. Repeat for the other sheets.
Arrange them tightly next to each other in a tray. Pour the prepared topping over them generously and bake in a preheated 356°F (180 °C) oven.