For the blueberry filling:

1. In a medium saucepan, whisk together 1/2 cup brown sugar, 2 tbsp cornstarch 1/4 tsp ground cinnamon, and a pinch of nutmeg. Add the frozen blueberries to the pan and stir until coated.
2. Add 1 1/2 tsp of fresh squeezed lemon juice and stir.
3. Over medium heat, stirring occasionally, bring the berry mixture to a boil.
4. Once boiling, stir constantly for 2-3 minutes or until the mixture begins to thicken.
5. Remove from heat and allow to cool.

For the cherry filling:

1. In a medium saucepan, whisk together 1/2 cup granulated sugar, 2 tbsp cornstarch, 1/4 tsp ground cinnamon, and a pinch of nutmeg. Add the frozen cherries to the pan and stir until coated.
2. Add 1 1/2 tsp of fresh squeezed lemon juice and stir. Over medium heat, stirring occasionally, bring the cherry mixture to a boil.
3. Once boiling, stir constantly for 2-3 minutes or until the mixture begins to thicken.
4. Remove from heat and allow to cool.

For the pie:

1. Once the fillings are cooled to room temperature, preheat the oven to 400 degrees and prepare the bottom crust in a 9″ pie pan according to the instructions on the package.
2. Alternate adding your fillings. This can be done by spoonful, in a striped pattern, or swirled gently together. Alternating the berry mixture gives the eater a surprise bite of berry each time. You can mix the berries together if you prefer.
3. After all of the berries are added to the pie, prepare the top crust. Cut stars and stripes, a lattice pattern, or use a traditional top crust with a few slits cut towards the center of the dough for the filling to vent.
4. Whisk together the egg and water, then brush the egg wash over the crust.
5. Place the pie on a rimmed baking sheet in the middle of the oven and bake for 25 minutes.
6. Remove the pie from the oven, cover the outside edges of the crust with foil, and return the pie to the oven to bake for another 30-35 minutes or until the filling is bubbling and the crust is golden brown.
7. Remove from the oven and cool on a wire rack before serving.