Please note: You should use a kitchen weight scale for best results with this recipe.
Preheat oven to 400F. Sift together all the dry ingredients. Cut in the shortening/butter until the pieces are about the size of green peas. Mix in the cheese, ham and chives. Add the milk and mix until everything is just evenly combined (the mixture won't be perfectly smooth, and may still be somewhat wet and crumbly).
Dust your counter with the extra flour and turn out the mixture onto it. Dust the top of the mixture, as well. Using your palms, flatten out the dough until it's about 3/4"-1" thick, ensuring it doesn't stick. Even it out with a rolling pin, if you like. Cut the biscuits into your favourite size and shape. Bake on a parchment-lined sheet pan until they are puffed up and golden brown, about 20-25 minutes. Yield: 15-20 biscuits