1-First: whisk together the marinade ingredients in a bowl: ketchup, packed dark brown sugar, soy sauce, canned pineapple juice, olive oil (divided), rice vinegar, garlic, ginger, sesame oil, salt, and pepper. Place the chicken cubes in a gallon-size resealable bag, reserve 1/2 cup of the marinade in the refrigerator, pour the remaining marinade over the chicken, seal the bag, and refrigerate for 1 hour.

2-Next: soak 10 wooden skewers in water for 1 hour if using them, to prevent burning. Preheat a grill to medium heat, around 400°F (200°C). Then, toss the bell pepper, red onion, and pineapple with the remaining 2 tablespoons of olive oil; season with salt and pepper.

3-Now, thread the red onion, bell pepper, pineapple, and chicken onto the skewers, alternating for even cooking. Brush the grill grates with olive oil, place the skewers on the grill, and cook for 5 minutes. Brush the tops with 1/4 cup of the reserved marinade, rotate the skewers, and brush the other side with the remaining 1/4 cup marinade.

4-Continue grilling for about 4 more minutes, or until the chicken reaches 165°F (75°C) in the center. Serve warm and enjoy the fresh flavors. This method takes about 25 minutes prep time, 15 minutes cook time, plus 1 hour marinade time, for a total of approximately 1 hour 40 minutes.