Combine the cherries, lemon juice, and sugar in the blender. Puree until smooth. Transfer to a jar and refrigerate until cold.
When ready to serve, fill glasses with ice and add about ⅓ cup of the cherry mixture to each glass. Add ⅔ cup still or sparkling water to each glass. Stir and garnish with fresh mint and additional cherries, if desired.
Notes
Fresh cherries may be used in this recipe. My go-to tends to be frozen, as it allows me to avoid pitting the cherries. If you are lucky enough to have an abundance of fresh cherries at hand, definitely make the most of them!