1 cup (160 g) cassava flour
½ cup (85 g) flax seeds
½ cup (70 g) sesame seeds
½ cup (60 g) sunflower seeds
½ teaspoon fine sea salt
1 cup + 2 tablespoons (265 ml) boiling water
¼ cup (55 g) olive oil, plus 2 tablespoons for brushing
flaky salt, for sprinkling
Position racks in the upper and lower thirds of the oven and preheat to 300ºF.
Stir together the flour, seeds, and salt in a large bowl.
Add the olive oil and water, stir to combine. Let sit at least 10 minutes, or up to an hour, to allow the water to be absorbed by the dry ingredients. When you can handle the dough with floured hands, then knead it in the bowl, into a smooth ball. Divide in two.
Roll one piece of dough between two pieces of parchment paper into a large, thin sheet that’s about the size of a baking sheet. Repeat with the other piece of dough.
Brush the dough all over with olive oil and sprinkle with flaky salt.
Bake the crackers until light golden, about 40-50 minutes (check at 15 minutes if using a different flour as some bake much faster than others).
Let the crackers cool, then break them into 2 to 3-inch pieces. If the crackers aren’t crisp enough after cooling, just return them to the oven for another 10 minutes or so.
Store the crackers in an airtight container.