2.
Lightly grease a roasting pan with cooking spray; season pork tenderloin with salt and fresh ground pepper and transfer to roasting pan.
3.
Arrange wedges of onions and apples around the meat and set aside.
4.
In a mixing bowl, combine apple juice, apple cider vinegar and mustard; whisk until thoroughly combined. Stir in sage.
5.
Pour the apple-dijon mixture over the meat.
6.
Cover with foil and roast for 1 hour.
7.
Remove foil and put back in oven, continue to cook for 20 minutes, basting the meat every 4 minutes with the juices in the pan.
8.
Remove from oven and let rest for about 10 minutes. Cut and serve.