My favorite cherry pie! This is my go to recipe for all my fruit pies! My husband loves cherry pie, so I usually omit the blueberries, but its a good recipe to follow.
I agree the filling does not thicken up very well... especially if you're using frozen fruit. I tried the following, and it fixes the problem well: I measure the cornstarch a little shy of the full 1/4 cup. Mix it into fruit as directed. Then, measure a tablespoon of instant tapioca, sprinkle about a quarter of it into the blueberries, the rest into the cherries, gently stir. The instant tapioca will thinken things up well. Need a "star" cutter? Check your child's Play-Doh set... mine had a perfect one! For our family, it wouldn't be 4th-of-July without this pie.