The next morning: Place all 3 flours in a large bowl and blend with the cardamom. Pour the water (save 20g to add with the salt), milk, honey and cooled butter in another bowl and add the preferment, stir until it is combined. Now pour the liquid onto the flour and mix until a dough forms and no dry flour remains, don’t knead. Cover and leave for 30 minutes.
Now add the salt with the remaining water, working it into the dough.
Cover and leave for 20 minutes, then do your first stretch and fold. Proceed with 3 more stretch and folds.
Cover and leave at room temperature for 3-4 hours or until the dough has almost doubled in size.
Place the dough on a lightly floured work surface, use either wholegrain or rye flour. Divide the dough into 18 pieces. Try not to over work the dough because you want to try and keep as much air in the dough as you can . Shape into rounds or rectangular buns. Place onto a floured tray, cover and leave for 60-90 minutes to prove, depending on the room temperature.
Preheat the oven to 230°C fan and place a baking tray on the centre shelf.
When you’re ready to bake place a deep tray of boiling water at the bottom of the oven. Slide the buns onto the hot baking tray and bake for 10 minutes. Now remove the tray of water and continue to bake for a further 5-6 minutes. Remove from the oven and let them cool down a little.
Divide the buns by sticking a fork around each bun to separate them in 2. Place the top and bottom with the cut side uppermost on the baking tray and bake for a further 5-8 minutes or until the are golden and toasted.
Next reduce the oven temperature to 100°C. (you'll need to expel the heat from the oven so turn the oven off and leave the oven door open for approximately 10 minutes) Dry the skorpor for approximately 1 hour or until they're dry and are crunchy.
Store in an airtight container for up 2 months.