For marinade, combine teriyaki sauce, garlic, and five-spice powder.
Place whole pork tenderloins in plastic bag set into a shallow dish.
Add marinade; seal bag. Turn meat to coat well. Chill 2 to 24 hours, turning meat occasionally.
Meanwhile, tear off a 36x18-inch piece of heavy foil. Fold in half to make a double thickness of foil that measures 18x18 inches.
Place pea pods and red sweet pepper in center of foil. Sprinkle with orange peel and brown sugar. Bring up two opposite edges of foil and seal with double fold. Then fold remaining ends to completely enclose vegetables, leaving space for steam to build.
Remove pork from bag, reserving marinade.
Arrange preheated coals around a drip pan in a covered grill. Test for medium heat above pan.
Place pork on grill over drip pan. Cover and grill for 30 to 35 minutes or until juices run clear (150 degrees F to 160 degrees F), brushing occasionally with marinade up to the last 5 minutes of grilling.
Add vegetable packet the last 15 minutes of grilling, turning packet once. Remove pork from grill and cover with foil.
Let meat stand for 15 minutes before slicing. Serve with vegetables. Garnish with green onion brushes, if desired.