Place the chicken, bell peppers, onion, and pineapple into a large mixing bowl.
In a saucepan over medium heat, whisk together the brown sugar, soy sauce, sweet chili sauce, garlic, salt, and black pepper until combined.
Bring the mixture to a gentle simmer.
In a small bowl, whisk together the cornstarch and water to create a slurry.
Slowly whisk the slurry into the sauce and continue stirring until thickened.
Remove from the heat and reserve ¼ cup of the glaze for brushing after grilling.
Pour the remaining glaze over the chicken and vegetables. Toss well to coat and marinate for 30 minutes.
Thread the marinated ingredients onto skewers, alternating chicken, peppers, onion, and pineapple.
Preheat the grill to medium-high heat.
Grill the Sweet Chili Hawaiian Chicken Skewers for 3–4 minutes per side, turning occasionally until the chicken reaches an internal temperature of 165°F (74°C).
Brush the skewers with the reserved glaze during the final minute of cooking.
Garnish with chopped chives or scallions and serve immediately.