Place a medium-sized pot over medium heat. Add cherries, sugar, salt, and 1/2 cup of water. Stir to incorporate and bring the mixture to a soft boil.
Use a vegetable peeler to zest the lemon in long strips. Then juice the lemon. Add the zest and just 1/2 tablespoon of the lemon juice to the pot. Stir to incorporate.
In a separate bowl, mix the cornstarch into the remaining 1/4 cup of water until it is completely dissolved and creates a slurry. Add the cornstarch slurry and stir until incorporated. Boil the sauce for at least one more minute to activate the cornstarch.
Continue to stir until the syrup in the cherry sauce is bubbling softly and has thickened enough to coat the back of a spoon. Take the cherry sauce off the heat, allow it to cool, and remove the strips of lemon zest. It will thicken as it cools. Enjoy!