In a small sauce pan combine cherries, sugar, lemon juice and water. Bring to a boil, and cook for 3-5 minutes until the sugar is completely dissolved and the cherries start to break down.
Pour into a blender or food process, or and process until smooth. Be careful when blending hot foods.
Place in fridge for 4-6 hours or until chilled.
Pour into your ice cream maker, and allow to churn for 20-25 minutes, according to the instructions. Put in an air tight container to freeze.
To serve scoop sorbet into a glass and pour chilled prosecco over the top.