In a large mixing bowl, combine pitted cherries and blueberries with sugar, lemon juice, and cornstarch. Toss well and let sit for about 10-15 minutes.

Roll out your chilled pie dough until about 1/8 inch thick. Transfer it to a 9-inch pie pan.

Pour the cherry and blueberry filling into the prepared pie crust, spreading it evenly.

Roll out another piece of dough for the top crust. Place over the filling, seal the edges, and cut slits for steam.

Preheat oven to 375°F (190°C). Bake for 50-60 minutes until golden brown and bubbly.

Cool the pie on a wire rack for at least 2 hours before serving.