Get ready the dough:
Dissolve the yeast and sugar in a small basin inside the warm water. Let it rest until it foams, approximately five minutes or so.
Combine flour and salt in a large mixing dish. Create a well in the middle and pour the olive oil and yeast mixture into it.
Stirring the components will help a dough develop. On a surface dusted with flour, knead the dough for five to seven minutes, until smooth and elastic.
After greasing a basin, cover with a moist towel and let the dough rise in a warm environment for around one hour, or until twice in size.
Get ready the cheese stuffing:
Combine the feta, ricotta and mozzarella cheeses in a medium bowl. Add, if using, the egg and minced parsley. Stirring until well blended.
Get the flatbread assembled.
Set your oven for 375°F (190°C).
Separate the dough in half exactly. Roll every component into a circle approximately one-fourth-inch thick.
Center half of the cheese mixture into each dough circle. Arange the cheese so that the edges have around one inch of dough around them.
Forming a round or oval shape, fold the edges over the cheese filling and squeeze the seams to seal.
To equally spread the cheese, gently flatten the packed dough with your hands.
Prepare the flatbread by:
