Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
If using rolled oats, blend into a fine flour.
In a bowl, mix oat flour, flaxseed, chia (if using), salt and spices.
Add water slowly, stirring until a thick, spreadable paste forms.
Spread mixture very thinly and evenly on the parchment (thin = crispier crackers).
Bake for 20–30 minutes, until dry and lightly golden.
Cool completely, then break into rustic pieces.