Preheat oven to 450 degrees. Add flour to sifter and sift into cup measure. Add the two cups of sifted flour to a bowl and form a well in the center. Cut in the shortening until it is evenly distributed and there are pea sized lumps. Greese a baking sheet pan. (Note: Na Na insists that the baking pan should be well seasoned, the darker the better.) Make a well in the center of the flour. Using your fingertips begin to knead the flour mixture while slowly adding the butter milk. The idea is to form a soft very moist mass in the center of the well. Once it comes together flip the whole mass a few times in the flour well and press lightly. (Note: the less you work with it the better, you don't want to develop any glutens like you would with yeast bread.) Squeeze off a small ball of the dough, roll in flour, press into the shape of a buscuit and place on the greased baking sheet. Or if you are not as practiced as NaNa you can turn the whole mass onto a baking sheet and flaten it to about 1/2 inch and cut out the buscuits with a biscuit cutter. Place the biscuits on the baking sheet and bake until the buscuits are brown on the bottom. (About 10 minutes) If they are not brown enough on the top turn on the broiler until they are brown enough but don't walk away when you have the broiler on or you will quickly have burnt biscuits.