Beat the egg with a little water, gradually add the sifted flour and salt and stir.
You need to get a dough that's a little thicker than pancake dough.
Transfer it to an oiled tray, place the crumbled feta cheese and butter on top.
Bake in a preheated 356°F (180 °C) oven until reddened.
Optionally, sprinkle with grated cheese.