In a medium saucepan, combine the fruit and 2 tablespoons honey. Cover and bring to a simmer over medium heat, stirring occasionally, until it begins to liquefy (about 5 to 10 minutes for berries, longer for firmer fruits). Once the fruit is liquidy, bring it to a gentle boil and let cook until it breaks down and becomes saucy, about 5 minutes. Mash lightly to reach your desired consistency (I kept mine fairly chunky).
Taste the jam for sweetness. If you desire more, stir in additional honey a few teaspoons at a time, until you reach the desired taste. Stir in any optional mix-ins.
Stir in the chia seeds and let cook one minute. Remove the pan from the heat, stir once more, and let sit for 10 minutes. The jam will continue to thicken as it cools. (If it seems very thin, add 1 to 2 additional teaspoons of chia seeds, stir, then let sit 10 additional minutes.)
Transfer the chia jam to an airtight container and store in the refrigerator for up to 2 weeks or freeze for up to 2 months.
Notes
Leftover chia jam can be stored in the refrigerator for up to 2 weeks or frozen for up to 2 months.