Peel and slice the peaches. Place in a large bowl. Add blueberries. Sprinkle with sugar and flour. Mix well and set aside.
Prepare the pie crust:
Sift the flour into a large bowl. Add butter and mix with a fork or pastry blender until the mixture resembles small peas. Make a well in the center and add the ice water. Mix together being careful not to over work the dough so that it does not become tough. Shape into a ball and refrigerate for 20 minutes.
Divide dough in half. On a lightly floured board, roll out one half into a 15″ circle. Carefully fold in half and place into a 9″ or 10″ pie plate. Press evenly onto bottom and sides of pie plate.
Evenly spoon the fruit mixture into the pie plate.
Roll out second half of dough and place on top of fruit. Pinch and crimp edges together. Make slits in top of dough.
In a small bowl, beat egg and brush over the top of the pie.
Bake at 400 degrees for 12 minutes. Lower temperature to 350 degrees and bake for 30 to 35 minutes.