To make the cherry pie filling, pitt the cherries over a medium bowl, reserving the juice.
Place the cherries and any juice from pitting into a medium saucepan over medium heat.
Stir in the sugar and lemon juice and cook until the cherries are soft.
In a small bowl, stir the cornstarch into the water to create a slurry.
Add the slurry to the pan of cherries and stir continually until the mixture thickens.
Remove from heat and leave to cool completely.
Preheat oven to 180°C/350°F/Gas 4 and spray a 9-inch/22cm deep pie dish with non-stick baking spray.
Place both premade pie crusts into the pie dish to create a thick crust.
Place three-quarters of the cooled cherry filling into the pie shell.
Bake in the preheated oven for 45-60 minutes or until the shell is a nice golden brown.
Remove from oven and leave to cool completely.
Place the chocolate chips into a medium bowl and set aside.
Using a small pan, heat up the heavy whipping cream until it's simmering.
Pour over the chocolate chips and leave to sit for 1 minute before whisking until smooth.
Transfer one-quarter cup into a piping bag or squeeze bottle and set aside.
Pour the remaining ganache over the cooled cherry pie and smooth it evenly.
Place the pie into the fridge to set and harden.
Once the ganache has hardened, scoop the remaining cherry filling on top and spread it out evenly.
Drizzle the chocolate ganache over the cherry pie.
Place into the fridge until ready to serve. Enjoy!