In a large mixing bowl, combine the pitted and halved cherries with fresh blueberries. Sprinkle in the sugar, cornstarch, and lemon juice, mixing gently until the fruits are well-coated. Let this mixture sit for about 15-20 minutes.

Preheat your oven to 425°F (220°C).

Roll out the pie crust on a lightly floured surface to fit a 9-inch pie dish. Pour the macerated fruit filling into the crust, spreading it evenly.

Roll out the second portion of dough for the top crust, position it over the filling, and cut a few slits for steam.

Bake the pie in the preheated oven for 15 minutes, then reduce to 350°F (175°C) and bake for another 25-30 minutes.

Remove the pie from the oven and let it cool for at least 2 hours on a wire rack.