Take the pastry squares from the freezer, separate them with a butter knife, and spread them out on the baking sheet to thaw (this will take just a few minutes).

In a mixing bowl, beat the two eggs, add the feta, and mix with a fork. Spoon ⅛ of this mixture onto the center of each pastry square.

When the pastry is still cool but just soft enough to bend without breaking, bring the opposite corners of each square together to make a triangular packet and seal the edges by pinching along their length. Bake for 35 minutes, until browned and flaky.