Add all marinade ingredients together in a bowl, and stir until well mixed. Place tenderloin in bowl, or in zip lock bag and pour marinade over tenderloin until well coated. Place tenderloin in fridge overnight or at least 4 hours.
Prepare and heat grill to 350°. Take tenderloin out of fridge to let it warm up.
Prepare apples, core and cut into ¼" slices. Gently toss with olive oil, brown sugar and fresh sage, use remaining to brush while grilling.
Remove tenderloin from marinade, and place on grill. Sear for 3-4 minutes on both sides. Lower heat. Place apples on grill, and grill apples for 3-4 minutes on both side. Remove apples when desired grill marks and color have appeared.
Continue cooking pork until tenderloin reached 150-160°F. Remove tenderloin from grill, and let it rest before slicing.
Heat olive oil in small pan on medium-high heat. Add fresh sage leaves for 20-30 seconds. Remove immediately, place on paper towel to dry.
Slice pork into medallions, arrange apples and crispy sage on platter. Serve and enjoy