Mix all the dry ingredients.
Add the oil and water and gently mix to form a dough.
Spread the dough on a sheet of baking paper and cover with another sheet so that the dough can be rolled flat with a rolling pin until it is about 3mm thick.
Cut the dough into smaller pieces or use a glass or other cutter.
Brush with egg and lightly sprinkle with the seed topping.
Bake the crispbread at 200°C (fan oven) for 20-25 minutes until the top is golden brown. Ideally bake several sheets at a time, rotating the sheets after 10-15 minutes.