Place blueberries in a small saucepan with just enough water to cover the bottom of the pan. Cook on medium low heat until berries are just soft and thickened.

Pour the berry mixture into a blender. Blend on high, combined with the oil and vinegar.  For a sweeter flavor, add Stevia to taste.  Allow to cool.

Store in a covered container in the refrigerator for up to 1 week.