Cook the strawberries: Add the quartered strawberries and vanilla paste to a small saucepan. Set over medium heat and cook for about 10 minutes, stirring occasionally, until the berries start to break down and release their juices.
Mash to desired consistency: Use a fork to mash the strawberries into a chunky jam. If you prefer a smoother consistency, you can blend the mixture in a blender or use an immersion blender.
Add chia seeds: Stir in the chia seeds and let the mixture simmer for another 1-2 minutes, stirring constantly. The jam will still look quite loose at this point, but it will thicken as it cools.
Sweeten if desired: Taste the jam (careful, it's hot!). If you’d like it a little sweeter, stir in honey or agave syrup to taste.
Cool and store: Pour the jam into a clean glass jar and let it cool to room temperature. Seal the jar and store in the refrigerator.
Because this jam contains no added sugar or pectin, it is more perishable than traditional jams. Always use a clean spoon or knife to scoop out the jam to avoid introducing bacteria.