Blueberry pie with frozen filling

Ingredients:

• 550 g (about 4 cups) blueberries
• 110 g (about 1/2 cup) sugar
• 1/8 tsp coarse salt
• 35 g (about 5 tbsp) tapioca starch
• 1 tbsp fresh orange juice
• 1 teaspoon orange zest
• 2 packs (255 g) of ready-made shortcrust pastry for pie
• 1 egg yolk, beaten with 1 teaspoon of water

Preparation:

1. Filling:
   
   Wash and dry the berries. Mash half the blueberries in a small bowl.
   
   In a medium bowl, combine sugar, salt, and tapioca starch. Add the mashed blueberries, orange juice, and orange zest and stir. Let the mixture sit for 15 minutes. Stir in the whole berries.
   
   Line a 9-inch (23-cm) pie pan with aluminum foil. Spread the blueberry mixture on the foil and freeze until firm, about 6 to 8 hours.
   
   Once the filling is frozen, remove the foil and wrap the mixture in plastic wrap. Store in a freezer bag in the freezer for up to 3 months.
2. Bakery:
   
   Preheat oven to 160°C.
   
   Roll out the first piece of dough and place it in a 9-inch (23 cm) pie pan, ensuring it extends to the edges. Trim any excess dough if necessary. Prick the bottom and sides of the shortbread base with a fork. Roll out the second piece of dough and cut it into strips 1-1/2 inches (2.8 cm) wide and at least 10 inches (25 cm) long. Use a 1-1/2-inch (2.8 cm) ruler: place the ruler on the dough, aligning one edge, and, turning it over, score the dough with the edge of the ruler.
   
   Remove the frozen pie filling from the freezer and place it on top of the prepared dough in the pan. Lightly brush the edges with egg yolk.
   
   Lay 4 strips of dough lengthwise on the filling, leaving equal distances between them. Fold back two strips (for example, the second and fourth) and place another strip in the center of the pie, perpendicular to the laid strips. Return the folded strips to their original position. Next, fold back the other two strips and place another strip to the left of the center, perpendicular to the laid strips. Return the folded strips to their original position and repeat the same steps on the other side of the perpendicular strips, folding back the same two strips as on the left. Once you have created a lattice, brush all the strips of dough with egg yolk, trim off any excess dough, and pinch the strips and edges of the base together.
   
   Place in the lower rack of the oven and bake for 1 hour 15 minutes. The pie should be bubbling slightly around the edges. If the center isn't browned enough, place the pie under the broiler for 1-2 minutes.
   
   Place the pie on a wire rack and let it cool to room temperature before serving, about 1 1/2 to 2 hours.