Cut each pork tenderloin into 4-5 pieces, pound pork pieces until 1/2" thick.
Marinate pork medallions in teriyaki sauce and onion slices for 4-6 hours
Preheat grill to high. Grill the Pork Medallions on high 3-4 minutes per side
If desired, place onions on a grill tray and grill for 5 minutes until soft, stirring occasionally. (Keep a close eye on the onions so they don't burn)
Sprinkle pork with sesame seeds and green onions if desired.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)