Preheat oven to 500 degrees F. Coat a 10 inch cast iron skillet with additional shortening or oil and place into the oven for 5 minutes. Put the flour into a bowl and cut the very cold butter into cubes and toss in the flour. Using a pastry cutter or two knives, cut butter into flour until it is crumbly. Add buttermilk and use a fork to mix very lightly. Dough will be very shaggy.
Put a bit of additional flour on the counter top and scoop dough out. Sprinkle a small amount of flour over the top and gently push together to form a rectangle. Do not overhandle the dough. Take the short sides of the rectangle and fold them in toward the middle. Turn the dough, gently press down into a rectangle again and fold again, repeat folding once more. Pat into desired thickness, usually 1/2 inch. This folding creates flaky layers in the biscuits.
Using a biscuit cutter or the rim of a small juice glass, cut out into rounds, taking care not to twist the cutter and gently gather scraps for the last biscuits. Transfer biscuits to the prepared skillet or baking pan and bake at 500 degrees F for 10 to 12 minutes, or until golden brown on top and cooked through.
Cook's Notes: This recipe uses self-rising flour - specifically a Southern soft-wheat type of white flour, such as White Lily. You may substitute regular all purpose flour, but you'll need to add 3 teaspoons of fresh baking powder and 1 teaspoon of salt. If using a cake pan or baking sheet, reduce temperature to 475 degrees F.
