Preheat oven to 475 degrees
In a food processor, pulse flour, baking powder, salt, & shortening.
Pulse in soy buttermilk.
Turn dough out onto lightly floured surface. Knead lightly, and punch the dough out to the approximate thickness desired. Cut with cup or biscuit cutter. Lightly reform leftover dough for more biscuits. Bake for approx 15 minutes or until desired doneness. If you'd like taller biscuits, place them next to each other and bake a bit longer.
If making the night before, cool completely before storing. I like to turn the oven to 350 and put them in while the oven is still cold, make the sausage & gravy, and then they're hot by the time I'm done without risk of burning. You can brush them with a bit of vegan butter for presentation, though I never do.