Preheat the oven to 180°C FAN (350°F) and line a baking tray with baking paper.
Add the chia seeds and 70ml (~¼ cup) water to a small bowl, mix well, and set aside to thicken for 8-10 mins.
Add the cashews and Parmesan to a food processor and blitz until finely ground, similar to coarse breadcrumbs.
Transfer the mixture to a bowl and add the chia mixture. By now, the chia seeds should be gel-like and will act as a natural binding agent. Mix until a uniform dough forms.
Place the dough between two sheets of baking paper and roll it out on a flat surface to around 2–3mm thick, making sure it’s evenly rolled for even baking. If you don’t have a rolling pin, the base of a glass works too.
Cut into small squares and arrange them on the prepared baking tray.
Bake for 15–20 minutes, or until lightly golden. Remove from the oven and allow the crackers to cool completely on the tray — this is essential for them to fully crisp up.