Filling: Cut the onions into thin slices. In a large bowl, mix the “souroto” cheese with the slightly beaten eggs, onions, salt and pepper. Dough: Knead all the ingredients together, add the yeast. Let the dough rise, cut in half and roll out two phyllo sheets. Brush the baking pan with oil and spread a layer of dough. Pour in the filling and cover with the remaining layer of dough.