Baked cheese pastries

For the puff pastry:
    1/2 cup Sitia Extra Virgin Olive Oil
    1/2 cup yogurt
    1/2 teaspoon baking soda
    1/2 teaspoon salt
    1 lb flour
    juice of 1 orange
 
For the filling:
    3/4 lb crumbled feta cheese
    1 egg

Prepare the dough: Beat olive oil with yogurt, add baking soda diluted in orange juice, salt and flour little by little until you achieve a soft and elastic dough.

Combine feta cheese and egg for the filling. Take pieces of dough the size of a walnut and roll each one out into a small circle. Place 1 teaspoon filling on 1 half and cover with the other half. Press the edges down with a fork to close firmly, baste with beaten egg white and bake in moderate heat until golden brown, about 25 minutes.