Preheat your grill to medium-high heat. If using an oven, preheat to 400°F.
In a large bowl, combine the chicken pieces, diced pineapple, red and green bell peppers, and red onion.
Drizzle the olive oil over the mixture, then add the BBQ sauce, garlic powder, onion powder, salt, and pepper. Toss everything together until well coated.
Place a portion of the chicken and vegetable mixture in the center of each piece of aluminum foil.
Fold the sides of the foil over the mixture, then fold the ends to create a sealed packet. Make sure it’s tightly sealed to prevent any leaks.
Place the foil packets on the grill or in the oven. Cook for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender.
Carefully open the packets (watch for steam) and garnish with chopped cilantro if desired. Serve immediately.