Sort and wash fresh blueberries. Dry on paper towels. Put sugar and cornstarch in a saucepan and mix. Add water and stir. Cook on medium heat until mixture begins to thicken. Add the berries and stir constantly until juice comes out and the berries soften--- approximately 10 minutes. Cool and refrigerate. Use over icecream or as a topping for cheesecake.

NOTE: For cheesecake, increase berries to 3 cups and cornstarch to 3 tbsp..