Rub the butter into the flour with the SPICY CHEESE BISCUIT BLEND and ¼ tsp salt until the mixture resembles fine breadcrumbs, then stir in the cheese.
Stir in the beaten egg and 2 tbsp water until the dough combines into a coherent ball (adding 1 tbsp extra water if too dry or a pinch more flour if too sticky).
Roll the dough into a large sausage shape about 5-6cm in diameter then wrap in clingfilm or a plastic bag and chill in the fridge for 20 minutes.
Preheat the oven to 190°C/gas mark 5.
Cut the dough into slices about 3-4mm thick. Place on parchment-lined baking trays then bake for 10 minutes or until golden brown and crisp.
