Begin by preparing the marinade by whisking brown sugar, soy sauce, pineapple juice, 2 tablespoons olive oil, rice vinegar, garlic, ginger, and sesame oil together in a small mixing bowl. Season with salt and black pepper, to taste and set aside.

Next, place chicken in a gallon-size Ziploc bag.

Reserving 1/2 cup of the marinade, pour the rest into the bag and toss chicken pieces to coat.

Seal the bag tightly and turn a couple of times until the chicken is thoroughly coated. Place the bag in the refrigerator for 1 - 2 hours.

When ready to cook, preheat a grill over medium heat to 400°F or a grill pan over medium-high heat.

Next, combine the red onion and bell pepper in a separate medium bowl and toss 2 tablespoons of olive oil. Season with salt and black pepper, to taste.

Remove the chicken from the refrigerator and discard excess marinade.

Thread red onion, bell pepper, pineapple, and chicken cubes onto metal skewers until all of the ingredients have been used.

Brush the grill grates or pan with the remaining olive oil.

Place your kabobs on the grill and cook for approximately 5 minutes.

Brush kabobs with the reserved (unused) marinade. Turn skewers and brush with remaining marinade and grill another 6-8 minutes, or until chicken is cooked through and no longer pink.

Remove from grill and serve immediately with your choice of sides.