In a medium bowl, combine first ten ingredients.
In a separate bowl, combine oil, soy sauce, vinegar, juice, green onions and the pepper.
Add wet ingredients to dry ingredients and whisk until dry ingredients are well incorporated. Reserve 3/4 cup of marinade.
Pour remaining marinade into a large resealable plastic bag. Add pork to bag. Marinate pork for a minimum of one hour.
Remove pork from bag and discard marinade. Grill over medium hot coals for approximately 45 minutes to 1 hour, turning halfway through cooking time, until juices run clear.
Baste pork with reserved marinade.
Alternatively, roast the pork tenderloin in a 400 degree oven for 15-20 minutes, turning halfway through cooking time, until a meat thermometer registers 140-145 degrees.