♦ The blueberries provide sweetness and the chia seeds provide the thickening agent. The consistency of your sauce/topping will depend upon how much chia you use. I recommend about 2 tsp of chia seeds per cup of berries for a thick sauce, more or less depending on the consistency you want. It will thicken more as it cools. If it ends up thickening more than you want, you can thin it out with some water or juice.
♦ You can use fresh (instead of frozen) blueberries, if desired. With fresh berries, I would suggest adding a splash of water to the sauce pan at the beginning along with the berries and chia, to help in the cooking process.