Place the pork tenderloin into a one-gallon freezer bag or other container
Whisk together remaining ingredients in a small bowl.
Pour the marinade over the pork and allow to marinate for at least two hours.
Preheat your grill to medium-high.
Remove the pork from the marinade and place it on the grill.
Close the grill and cook 20-25 minutes, turning every couple of minutes to ensure even cooking.
Transfer to a cutting board to rest for 5 minutes.
Slice, garnish with fresh sliced oranges if desired, and serve.