1. Combine pepper and salt. Rub evenly over pork tenderloins, and place on a lightly greased rack in a roasting pan.
2. Bake at 450° for 20 to 25 minutes or until a meat thermometer inserted into thickest portion registers 155°. Let stand 10 minutes before thinly slicing. Reduce oven temperature to 425°.
3. Combine yeast, sugar, and 3/4 cup water in a large bowl; let stand 5 minutes.
4. Add baking mix and next 4 ingredients to yeast mixture, stirring until dry ingredients are moistened. Stir in flour (up to 1/2 cup) as needed until dough pulls away from sides of bowl. Turn dough out onto a lightly floured surface, and knead gently 2 to 3 times.
5. Pat or roll dough to a 1-inch thickness; cut biscuits with a 1 1/2-inch round cutter. Place biscuits on lightly greased baking sheets.
6. Bake at 425° for 10 to 12 minutes or until lightly browned. Split biscuits; serve sliced pork in biscuits with mustard.