Remove the dough from the fridge and divide it in half.
Roll out thinly the first part of the dough on a piece of parchment paper (the second part of the dough returns to the refrigerator) into a large square that’s about ⅛-inch (3-4 mm) thick. It’s important that the dough is well sprinkled with flour, it is a little more sticky than traditional shortcrust pastry. While rolling it out, lift the dough and make sure it doesn‘t stick to the paper.
Use a sharp knife to cut out any hand pie form you like (I cut 10 x 10 cm / 4 x 4 inch squares).
Lift a piece of dough, just to make sure that it doesn‘t stick, then put it back, scoop about 2 tablespoons blueberry filling (or as much as will fit), leaving about ⅓-inch (¾ cm) border. Cover with a second piece of dough, seal the edges together with your fingers, then press the edges of the dough together with the tines of a fork (it doesn‘t have to be sealed very well). If the dough sticks to your fingers or fork, dip them in flour. Prick the dough with a fork a couple of times on top of each pie.
Place the pies on a baking sheet lined with baking paper. Bake the pies in batches (the remaining ingredients go to the fridge). Arrange the pies at least an inch / 2.5 cm apart on baking paper.
Make the egg wash: beat an egg with a tablespoon of milk. Brush the pies with the egg wash. You can sprinkle them with granulated sugar for extra crunch.
Bake for about 30 minutes, until the pies are golden.
Repeat with the rest of the dough.
Enjoy!