Position a rack in the center of the oven and preheat it to 425F
Butter the cookie sheet or cover it with parchment paper
In a large mixing bowl whisk together the flour, baking powder and salt
Cut in the butter and shortening until it resembles coarse meal
Add the milk and toss it in only until the dough hold together. (If the dough is becoming sticky place it in the fridge for 5 - 10 minutes)
Add a drop or two more milk if the dough is too powdery
To make drop biscuits, scoop 10 equal portions of the dough onto the baking sheet, placing them at least one inch apart
Bake 12 to 15 minutes until a light golden brown on top.
Cool on wire rack, serve warm