Begin with the blueberries. Pour approximately 100ml freshly boiled water over the berries. Soak for 15 minutes. Drain (keep the liquor to add to a smoothie). Dry with kitchen paper.
Place the dates, walnuts, almonds, cashews and salt in a high speed blender. Add a third of the blueberries. Blitz until you have a relatively smooth dough. Remove from the blender and place in a bowl. Add the remaining blueberries, with your hand, work them into the dough. Form into four sausages, squaring off the sides. Roll in desiccated coconut, Wrap in greaseproof paper and pop in the fridge for an hour or 2 to firm up. Cut into slices. They keep in the fridge for up to 10 days, wrapped in greaseproof paper.