Roll dough into pie pan and chill. Preheat oven to 425. Whisk
together egg and milk for egg wash. Combine blueberries, lemon
juice, sugar, flour, and cinnamon. PLace in crust with butter on
top. Roll second pie crust on top. Chill for 25 minutes. Brush with
egg wash and bake for 20 minutes, reduce heat to 350 and bake
for another 30-40 minutes.