Step 1

Mix together the dry ingredients. Add the shortening. , Using your fingertips, a pastry blender, or a stand mixer, incorporate the shortening into the flour mixture until the consistency resembles bread crumbs., Cut cold butter into 1/2" chunks, add to flour mixture and toss to coat., With your fingertips, a pastry blender, or a stand mixer, flatten the chunks of the butter until there aren't pieces larger than the size of a dime. , Whisk the egg and milk together. Add them to the dry ingredients all at once, mixing quickly and gently for about 20 seconds until you have a soft dough., Dump the dough onto a lightly floured work surface. Knead it a couple of times to bring it together. With the help of a dough scraper, shape the dough into a 6" x 6" square, about 3/4" thick. Run a rolling pin over the top once to even it out. Wrap it in plastic wrap, and place it in the freezer for 1 hour., Preheat the oven to 400°F., Remove the dough from the freezer, unwrap it, and set it on a work surface. It'll be very stiff, but still soft enough to cut with a sharp knife, sharpened dough scraper or rolling cutter (pizza cutter). Cut the dough into nine 2" squares, and place the squares on a lightly greased or parchment-lined baking sheet.

Step 2

, Bake the biscuits for 16 minutes, or until they're a light, golden brown. Remove them from the oven, and serve hot, warm or at room temperature.

Step 3

, Store leftover flaky biscuits well-wrapped, on the counter for 3 days. Freeze for up to 3 months.