Place blueberries, sugar, and two tablespoons of water into a wide, shallow pan. Warm the mixture over medium heat, simmering until the blueberries become tender and burst open, roughly 5 minutes.
Crush the berries with a potato masher and keep cooking for 5-10 minutes until the fruit reaches a sauce-like thickness. Cool for 15 minutes.
Once cooled, use a blender or food processor to combine the blueberry, milk, and cream. Chill in the refrigerator for at least an hour until cold. Separation of the mixture during this time is quite normal.
Follow the instructions for your ice cream maker to churn the mixture. Once churned, scoop the ice cream into a freezer-safe container and allow it to harden for at least four hours.
Notes
Place the blueberries in the fridge for at least a few hours or, preferably, overnight to cool completely. Even slightly warm ingredients will create an icy, less creamy dessert.