Preheat oven to 450ºF (230ºC).
Combine the flour, baking powder and salt in a large bowl.
Cut in butter, either using a food processor, or hand cutter.
Add starter, and mix well (using hands if necessary).
On a lightly floured surface roll dough out to about 1 inch thickness.
Cut biscuits using a round cutter. Place on a tray and let them rest for 12-15 minutes.
Place biscuits in the oven, and bake for about 20 minutes or until golden brown.
Once baked remove biscuits from the tray immediately and place on a cooling rack.