The sauce is best prepared ahead of time (8 hours or day before.)
In a small bowl, mix together apple jelly, pineapple fruit preserves, prepared horseradish, ground dry mustard, and cracked black pepper.
Place all spices in a bowl and mix well. Add olive oil. Rub the mixture into the exterior of the pork tenderloins and let them rest for 15 minutes.
Grill for 25 to 35 minutes (depending upon your grill), or until the internal temperature is 155°-165°. (This can also be roasted in the oven). Slice and serve with Jezebel Sauce on the side. (Extra sauce will keep in the refrigerator for up to 2 months.)