Cut chicken, bell pepper, red onion and pineapple into bite-sized chunks. Place in separate bowls.
Start layering ingredients onto your skewers, alternating chicken, bell pepper, red onion and pineapple chunks. Place skewers on a large plate or cutting board. Repeat until you have 5-6 full skewers. Brush all evenly with 1/4 cup BBQ sauce, and sprinkle with salt and pepper.
Preheat your outdoor gas grill or grill pan to medium-high heat. Once hot, place skewers on grill and cook on all sides until chicken is cooked and vegetables have softened, 9-10 minutes. With a clean brush, coat skewers again with 1/4 cup more BBQ sauce. Carefully remove from heat and let cool slightly.
To remove cooked skewers to a plate, slide a fork from the top to the bottom of each skewer.
If using wooden skewers, soak in water for 10 minutes before skewering with ingredients. This will prevent them from burning on your outdoor grill/grill pan.