Preheat oven to 500°F for 15 minutes before baking.
Spray a cookie sheet with non-stick spray or line with parchment paper.
In a large bowl, whisk together flour, baking powder, salt, dry mustard (optional) and baking soda.
Place the cheese in a blender or food processor to coarsely grind (or use a hand grater).
Add grated cheese and sour cream to flour mixture and mix well.
Turn dough out onto a lightly floured board and knead gently for 1-2 minutes. Roll out to a 3/4 inch thickness. Cut out with a biscuit cutter dipped in flour.
Bake for 10 minutes or until golden brown.
Submitted by: CM
