2) Turn the dough out onto a lightly floured board and knead a few times. Divide in half, cover with cling film and leave to rest at room temperature for 10 minutes. Preheat the oven to 190C/Gas 5.
3) Put a silicone baking mat on your work surface and roll the dough into a rectangle, about 15cm by 23cm and 0.5cm thick. Evenly trim the edges, adding back any trimmings to the second portion of dough.
4) Cut 5cm strips with a knife, but leaving the dough in place. Then cut diagonals to form triangular pieces, 5cm on their long side. Repeat, gently transferring them to a baking sheet fitted with a silicone baking mat, spacing them 2.5cm apart. Repeat with the second half of dough.
5) Bake for 9 to 12 minutes, checking carefully after 9 minutes. The crackers will start to turn golden. Remove from the oven and leave to cool. Store tightly covered for up to 3 days.