To make the Huli Huli marinade, combine all the ingredients in a mixing bowl and mix well. Make sure the brown sugar is dissolved. Set aside 1/2 cup of the marinade for basting.
Place the chicken thighs in the marinade and place in the fridge for at least 1 hour. Overnight for optimal flavor.
Set the grill to high direct heat at 450 degrees.
Place the marinated Huli Huli chicken thighs on the grill. Flip every 2-3 minutes or until the meat reaches 165 degrees internal temperature. Baste with the reserved marinade every time you flip.
Add a few slices of pineapple on the grill to get a nice char on them. It's a great side for the chicken.
When the chicken thighs reach 165 degrees remove them from the grill and let them rest. They will get up to 175 degrees leaving the chicken tender and juicy.
Before serving, drizzle with sriracha mayo for an extra kick and garnish with sesame seeds and green onions.