Preheat your oven to 375°F (190°C). Roll out the pie dough on a floured surface to 1/8 inch thick and fit into a 9-inch pie pan.

In a large mixing bowl, combine cherries and blueberries. Add sugar, cornstarch, and lemon juice; stir until well-coated.

Pour the fruit filling into the prepared crust, and if desired, add a lattice pattern with extra pie dough.

Bake for 45-50 minutes until filling bubbles and crust is golden brown. Cover edges with foil if browning too quickly.

Cool at room temperature for at least 2 hours before serving to allow filling to set.