If using fresh cherries : In a saucepan, put cherries over medium heat. Cover the pan and heat the cherries until they begin to simmer in their own juices (10-15 mins), stirring often.
If using dried cherries, follow the instructions above, however, add the 2 cups of water to the cherries as they begin to heat and continue on.
In a medium bowl, whisk the sugar with the cornstarch. Add the lemon juice to cherries in pot and then pour the sugar mixture into the hot cherries and juice and mix well. Drop heat to low, bring to a simmer, and cook until the filling has thickened, about 2 minutes. Enjoy!