Preheat the oven to 350 degrees Fahrenheit.
In a small bowl, beat the egg and water together to make an egg wash. Set aside.
Divide 1 half of the dough into 5 equal pieces. On a floured surface, roll out one piece of the chilled dough into a 5-inch oblong circle(or slightly larger). Don't worry if the edges are not perfectly shaped.
Spoon about 3 heaping tablespoons of the filling onto one half of the dough circle.
Brush the edges of the dough with the egg wash. Fold the other half of the dough over the filling to form a semi-circle.
Press the edges firmly to seal, then use a fork or pastry crimper to create a decorative edge and ensure a tight seal. Trim off any excess dough to create a neat and uniform appearance.
Place the assembled patties on a baking sheet lined with parchment paper.
Repeat the process with the remaining dough and filling until all the patties are assembled.
Bake the patties in the preheated oven for 30-35 minutes, or until the crust is crisp and slightly brown on the edges. Once baked, transfer the patties to wire racks to cool slightly before serving.