Preheat your oven to 400℉.
If needed, grind your flaxseed ¼ cup at a time in your coffee grinder. Add to your mixing bowl.
Then, grind the ¼ cup tiger nuts.
Then add 1 cup of water and mix until combined. It should be soupy (about as runny as pancake mix), but you may need to add up to ¼ cup more water to get this consistency. The flaxseed will thicken quickly.
Line your baking sheet with unbleached parchment paper or silicone mat(s).
Pour the mixture across the baking sheet and spread it as thin as you can. Take care to make sure there are no holes.
Once it's all smoothed out to less than ⅛ inch, make sure it is not thinner at the edges than the middle. This will help it to cook evenly and to prevent it from burning.
Place in the oven and set a timer for 30 minutes. It will likely take closer to 40 minutes but in case your oven has a hot spot, check it.
You’ll know it’s done when the edges are brown, and the center is crisp.