Begin by washing your mixed berries thoroughly, then place them in a medium saucepan over medium heat. Use a potato masher or fork to mash the berries, cooking for about 4–5 minutes until they soften and release their juices.

Once the berries are softened, add in the chia seeds, maple syrup, lemon juice, and vanilla extract. Stir the mixture well with a wooden spoon for about 1–2 minutes.

Reduce the heat to low and allow the mixture to simmer gently for another 5–10 minutes, stirring occasionally until it thickens to a jam-like consistency.

Once your jam has reached the desired thickness, remove the saucepan from heat and let it cool for about 10 minutes. Then transfer the jam into an airtight container or jar.