01 - Place mixed berries in a medium saucepan over medium heat. Cook, stirring occasionally, until berries begin to break down and release their natural juices, approximately 5 minutes.
02 - Use a fork or potato masher to mash the cooked berries to your preferred texture, whether chunky or smooth.
03 - Stir in the maple syrup or honey, chia seeds, vanilla extract, and lemon juice until thoroughly combined.
04 - Remove from heat and let the mixture rest for at least 5 minutes, stirring occasionally to distribute the chia seeds as they absorb liquid and thicken the jam.
05 - Taste the jam and adjust sweetness level with additional sweetener if desired.
06 - Transfer the jam to a clean glass jar. Allow to cool completely at room temperature before sealing and refrigerating.
07 - Store in the refrigerator for up to 1 week. Always keep chilled as this is not a shelf-stable preserve.