Place the frozen fruit in a small saucepan and gently heat until not only thawed through but the fruit has begun to break down.
Before the fruit turns into total mush, remove the saucepan from the heat, transfer the fruit mixture into a bowl and allow to cool slightly.
Taste the fruit and add the agave and lemon juice and zest to taste (more or less will be needed depending on the tartness of the fruit).
Stir in the chia seeds, decant the mixture into a sterilised glass jar and once completely cooled store in the fridge overnight.
The next day the chia jam will have set and is ready to use.