Preheat the grill to medium-high heat.
Make the Teriyaki Sauce: The sauce can be made inside on the stove or directly on the grill using a heat proof saucepan.
Add the tamari, mirin, brown sugar, honey, sesame oil, garlic, and ginger into a small saucepan, and bring to a low boil.
In a small dish, combine the water and cornstarch to create a slurry. Mix until very smooth. Add the cornstarch slurry and whisk to incorporate. Bring back to a low boil then and whisk until just beginning to thicken.
Remove from heat and set aside.
Grill the Chops: For medium rare chops: Place the chops directly over the heat, and sear until light grill-marks appear, 2 to 3 minutes. Flip, then brush the teriyaki glaze over the cooked side. Cook for 2-3 minutes more then flip and brush the teriyaki sauce over the second side. Flip back and cook for another minute or until an instant read thermometer reads 130°F when inserted in the centre of the thickest part of the chop, do not touch the bone.
(For medium chops add about one minute per side. Cooking times will vary)
Transfer the chops to a platter, cover loosely with aluminum foil and let rest.
For Serving: Sprinkle the chops with sesame seeds and green onions. Serve with rice, a Korean Green Salad, and extra sauce.