Instructions

1. Have the flaxseed base ready and already gelled before the seeds go anywhere near it. Flax needs time in water to thicken, and adding seeds to a base that has not set gives you a mixture that will not hold a shape.
2. Stir the sunflower, sesame and pumpkin seeds through the base until every seed is coated. Any dry seed on the surface will fall off the finished cracker rather than staying in it.
3. Spread the mixture onto a drying sheet in a square about as wide as your tray, and work it to one even depth with a rubber spatula. Run a straight edge round the outside for clean sides, since a ragged edge dries hard and snaps off.
4. Keep it thin enough that you can see the seeds sitting proud of the surface. A thick sheet takes twice as long and still ends up soft in the middle.
5. Dehydrate at 52 °C for 3 hours, which is only long enough to firm the surface — this first stage exists so you can cut the sheet cleanly rather than break it later.
6. Cut the firm square into crackers with a pizza wheel, pressing all the way through to the sheet. A half-cut line tears wherever it likes once the sheet is dry.
7. Return the tray for another 9 hours, turning the crackers over onto mesh once they will lift in one piece. The underside is the damper face and will stay chewy if it never gets air.
8. They are done when a cooled cracker snaps with a clean break and no darker damp band through the middle. Store them in a rigid airtight tin for a fortnight — pumpkin and sunflower oils both turn, and a stale one tastes bitter well before it goes soft.