Soak the dates in hot water for 15 minutes, then remove them from the water and discard the pits.
Place the blackberries, chia seeds, dates and 3 tablespoons of the soak water into a food processor and blend until smooth (approximately 2 minutes).
Pour into a clean jar with a lid. Place in the fridge for a few hours or overnight to allow the jam to thicken before using.
Notes
Makes approximately 220g blueberry chia jam or 1 medium size jar. Will keep in an airtight container in the fridge for up to one week. Freeze in a suitable container for up to three months.