Preheat oven to 475 degrees F.

Combine flour, salt, baking powder and baking soda and sift 3 times. Add cheese, mustard powder and cayenne to the mix.

Using a pastry cutter or your hands combine butter and dry ingredients until it resembles coarse beach sand.

Add almost all of the milk and mix until a sticky dough forms - add the remaining milk if necessary (the wetter the dough the lighter the biscuits will be).

To achieve an even crumb to the dough very gently knead the dough 4-5 times on a lightly floured surface. To achieve a layered effect knead very gently once then fold and turn the dough 3-4 times until dough has formed a smooth texture.

Pat dough into a 6 inch by 4 inch rectangle and use a biscuit cutter to stamp out (without twisting) the rounds. Combine scraps to stamp out the last biscuit. Or use a floured sharp knife to cut the dough into biscuits.

To have soft sided biscuits place the rounds just touching on a baking dish, or place them further apart to have crisp sided biscuits.

Bake in very hot oven 8-10 minutes until biscuits are well risen and lightly colored on top. Serve warm.