Cut the pastry in half; roll out until you can cut 16 rounds with a 10cm pastry cutter (I used a cup). Place aside.
In a bowl, mash the feta cheese with a fork, mix in mozzarella and then add the eggs. Put a tablespoon of the filling on one half of each round of pastry. Slightly dampen the pastry edges then fold the pastry over the filling to make a half-moon shape. Seal the pies by pressing down with the prongs of a fork and brush with reserved beaten egg for a presentable finish.
Place on sheets of aluminum foil on a baking tray and bake them in a preheated oven at 200C for 15-20 minutes, or until they are puffed up and golden.