Preheat oven to 350F – 180C.
In a bowl, whisk all the dry ingredients together.
Add the butter, using dough/pastry cutter, or two forks, cut the butter into the dry ingredients.
Add the milk, and using a fork mix the dough gently, just so it gets wet.
Do not knead this dough or over mix it.
Place the dough on a floured working surface, and dust dough with little flour.
Fold the dough couple or three times on itself, then roll it out about 3/4 inch thickness.
I have used a knife to cut but you can use a cookie cutter.
Place the biscuits on baking sheet. Brush with milk and sprinkle with some sea salt.
Bake for 13 -15 minutes or until golden brown and inserted toothpick in the middle of the biscuit comes out clean.