Preheat the oven to 400 degrees. Line a baking sheet with parchment paper or a silicone baking mat.
Whisk together the flour, starch, baking powder and salt. Cut the fat into the flour either with a pastry cutter, two knives, or by rubbing the fat into the flour with your fingers. Make sure you leave some larger pieces of fat.
Add the liquid, starting with ½ a cup and gradually adding a little more at a time, mixing until the dough comes together.
Put a little flour on a work surface and dump out the dough. Knead 3 or 4 times then either roll or pat it out to about ½ inch thick. Cut into biscuits using a 2½-inch cookie cutter. You can gently reform the dough to cut more biscuits.
Place the biscuits on the prepared baking sheet and bake for 20 minutes or until lightly browned. Serve warm.