In a small bowl, whisk together sauce ingredients well, so that sugar dissolves. Divide in half and store half for basting later.
Soak bamboo skewers in water at least 30 minutes, preferably overnight.
Cut chicken breasts into 1" cubes.
Place chicken in plastic bag or large bowl and cover with half huli huli sauce to marinate. Marinate at least 30 minutes, preferably overnight in the refrigerator.
After chicken is marinated, preheat grill to medium high - between 425 and 450 degrees.
Cut onion, pineapple, and peppers into 1" cubes.
Remove skewers from water. Slide chicken, peppers, pineapple, and onion onto skewers, alternating as you place on the skewers.
Brush a small bit of marinade onto the skewers and place onto the grill. Discard any leftover marinade and be sure to wash hands well after handling raw chicken.
Cook chicken for 5 minutes. Then, turn the skewers to the opposite side, and cook for an additional 5 minutes, or until the internal temperature of the chicken registers 165F on an instant read thermometer.
Brush the kabobs with huli huli sauce you saved to baste with and cook for an additional 2-3 minutes, or just until the huli huli sauce is warmed through and becomes a bit sticky.
Remove from grill and let rest 5 minutes - garnish with fresh chopped parsley or cilantro if desired.
Enjoy!