If you're using bamboo skewers, you will want to soak them in water for 20 minutes before using them. You can also use metal skewers, just be careful when handling them on the grill as they get hot.
Cut the chicken in 1" cubes and skewer them, alternating with 2 pieces of green onion, leaving at least 2" on either end of the skewer.
Lightly oil the grill grates (to prevent sticking) and heat it to 400F.
If using just the salt, sprinkle with sea salt on both sides.
Make sure the tare sauce is ready (if you're using it) before you start grilling
Place the chicken on the grill and cook 3-5 minutes per side, until browned on the outside.
If just using salt, remove it from the grill when the outsides are caramelized (about 7-10 minutes total).
If using the tare sauce, baste the chicken with it when it's about 75% done cooking.
Flip it over and baste the other side. Repeat this process one more time and remove from the grill when chicken in done.