A lot of jams use plant-based pectin or animal-based gelatin to achieve their texture, and these need to be cooked to set. An easier route is to use chia seeds, which naturally gel when left in liquid, to make an easy jam that’s loaded with omega-3 fatty acids and calcium. The lemon juice will keep the jam fresh for longer.
For a smoother texture, grind the chia seeds in a clean coffee grinder or spice grinder before adding to the fruit. Alternatively, combine all the ingredients in a small blender and purée to your desired consistency.