Preheat the oven to 220C/428F.
In a medium mixing bowl, combine the psyllium husk powder, seasoning and spices. Whisk as you pour in the hot water – it will gel up very quickly, so whisk quickly! Once you have incorporated all the psyllium husk, set aside a little to cool.
Add the hemp seeds and parmesan dust to the bowl. Get your hands in there and start pulling apart the psyllium gel and incorporating all the ingredients. Knead the dough in the bowl and keep going until you have incorporated 99% of the hemp seeds into a ball of dough. This takes about 5-10 minutes and skipping through it will only you deprive you of a delicious cracker. Take the time and do it right.
If your dough absolutely will not come together into a (relatively dry but cohesive) ball, add another 20ml water. Knead the dough again and try to bring it together. We want to add as little water as possible to form a dough so that the crackers will stick together but crisp up beautifully. We want to ensure everything is totally combined as sections that are all hemp seed and no binder will not stick together.
Take a large sheet of baking paper and place the dough ball onto the paper. Use a moistened hand to mould it into a rectangle of any size but with nice even sides (this makes it easier to roll out nicely). Use moistened hands to rectify any sections that look overly dry (but try not to overdo it).
Place another large sheet of baking paper on top. Use a rolling pin to gently roll the dough out into a large thin rectangle – around 36cm X 26cm. The crackers should be ½ centimetre thick or slightly less – thicker than this will take longer to cook and might not be pleasant to eat.
When the crackers are uniformly and evenly rolled out thinly, peel off the top layer of baking paper. Neaten up the edges using slightly moistened hands and patch any areas of excess hemp seed together with a tiny amount of water if necessary.
I always wing it with my cracker size but a batch I enjoyed recently was 8cm X 6cm – a nice rectangle for dipping. This made 16 crackers – some around the edges were slightly larger.
Whatever you choose, use a sharp non-serrated knife to slice the crackers into your desired shape.
Gently pull the baking paper under the crackers onto a large baking sheet with enough room for all the crackers (we don’t want them baking unevenly up the edges of the baking tray. If you don’t have one big enough, you can invert the baking tray (no edges) or bake the crackers on two trays (carefully use scissors to slice the baking paper under the crackers and work carefully to divide the sheets of crackers).
Bake the crackers for 10 minutes, then turn the oven down to 120C/248F and bake for an additional 30-40 minutes. The crackers around the edge tend to bake up earliest – you can see they are brown and feel solid to the touch. Remove these and place them on a wire rack to cool. Continue to bake the rest of the crackers until they are golden brown and feel solid rather than soft if you press on them. I find it helps to divide the crackers into individual crackers with your knife and then spread them out to finish baking. For me, this takes around 10-20 minutes longer but it depends on how thinly you rolled them to begin with (thinner crackers = faster baking time). It also depends on whether you added more water to the dough (more water = longer baking time).
Once all the crackers are fully cooked, separate them and place them on the baking tray to completely cool. Transfer them to an airtight container.
I find the hemp seed version is the crispiest and stays crispy for a number of days – no batch has lasted longer than this at my house.