1. Allow crusts to come to room temperature for easy handling. Follow box directions for a double crust pie. Line bottom crust in deep 9" - 10 "pie plate.
2. Fill a pot with water deep enough to cover peaches. Bring water to a boil. Place rinsed peaches into the boiling water for no more than 1 minute and drain immediately; then place peaches in bowl of ice water to cool. Drain. The skins will peel off easily. Slice peaches into 8-10 wedges per peach. Sprinkle peaches with lemon juice.
3. In a large bowl, mix together the sugar, cornstarch, flour, and cinnamon. Add to peaches and blueberries. Mix well and allow to rest for 5 minutes. Then, pour into bottom crust.
4. Dot with diced butter.
5 Place second crust on Top, Crimp edges and make 5 slashes in top crust to keep juices from spilling.
6. Brush water and egg mixture on top crust and edges. Sprinkle sugar on top. Bake at 425 degrees for 15 minutes. Reduce heat to 375 degrees and bake 45 minutes longer. Cool. Serve with vanilla ice cream.