Mash fruit: Add fruit to a small saucepan over medium-high heat. Mash with a meat masher or fork to break down the fruit and cook for about 5 minutes, until all the fruit is broken down and slightly thickened. Use an immersion blender if you want it really smooth.

Stir in chia seeds. Remove from heat and stir in lemon juice. Taste and add sweetener if needed, depending on the type of fruit used*.

Pour chia seed jam into containers* and store in the fridge for up to 1 week, or freeze for up to 3 months.