Preheat the oven to 350°F.
Mix the corn starch into the cherry pie filling, then pour the filling into one of the pie crusts.
Flip the other pie crust on top of the pie, and use a fork to seal the edges together (refer to the package instructions for exact details, as some instructions differ).
Cut slits into the top of the pie, then brush it with milk and sprinkle sugar evenly over the top.
Bake the pie on the middle rack uncovered for 35-45 minutes until golden.
Let it rest for a few minutes to thicken before serving.
