Line a large baking tray with parchment paper or aluminium foil.
First make the filling: place the blueberries, chia, and honey in a small saucepan over medium heat. Cover and cook just until the blueberries start to pop – about 7 mins. Squish them down slightly with a spoon.
At this point, the chia will have absorbed all the liquid. You're looking for a chia-pudding-like consistency. If it appears too dry, add more water and cook. If it's too loose add 1 tbsp more chia and cook for 2 mins.
Stir in the lemon juice. Taste and add more honey if necessary.
Dollop small spoonfuls of the filling on the baking tray. Leave a gap between each. Freeze for at least an hour. This can be done up to a week in advance.
Break the chocolate bar into small pieces. Microwave on low in 1 minute bursts until melted. Stir between each run. Set aside to cool completely.
To assemble, we need the berry-chia filling frozen solid and the chocolate at room temp. Dip each berry puck liberally in chocolate.
Return each disc back to its spot on the baking tray. Do this quickly before the fillings start to melt. (If it melts, put back in the freezer and repeat.)
Place the tray in the fridge until the chocolate sets – about 10 mins. Once set they’re ready to eat. Keep refrigerated in an airtight container.