Method

• Prepare the bottom crust: Remove a dough disc from refrigerator and let sit for 5 to 10 minutes to take the chill off. Place it on a lightly floured clean, flat surface. Roll it out into a circle about 13 inches wide. Place the rolled out dough on to a 9-inch pie pan. Trim the edges to ½ inch over the edge of the plan. Place in the refrigerator to chill.
• Make the blueberry filling: Pull the second disc of dough from the refrigerator so it can come to temp while you make the filling. Place the blueberries, sugar, cornstarch (or flour or quick tapioca), cinnamon, lemon zest, and lemon juice in a large bowl. Gently stir them so that all of the blueberries are coated with some sugar and flour.
• Fill the bottom crust: Remove the bottom crust from the refrigerator and place the sugar coated berries into the pan.
• Roll out the second dough disc: Use a rolling pin to roll the dough to the same size and thickness as the first. Place on top of the berry filling. Tuck the top dough over and under the edge of the bottom dough, and crimp the edges with your fingers. Place in refrigerator while you make the egg wash.
• Preheat the oven: Place the baking rack in the middle of the oven and preheat to 425°F.
• Brush the pie with the egg wash: Whisk egg and milk together to make an egg wash. Brush the top crust with egg wash. Score the pie on the top with several cuts (so steam can escape while cooking).
• Bake the pie: Place the pie on the middle rack of the oven with a foil or Silpat lined baking pan positioned on the lower rack to catch any filling that may bubble over. Bake for 20 minutes at 425°. Reduce heat to 350°F and bake for 30 to 40 minutes more or until juices are bubbling and have thickened.
• Cool the pie, then serve: Transfer to a wire rack to cool. Let cool completely before serving.