Add onion and red bell peppers to the bottom of a 6-quart slow cooker. Then, place the chicken on top.
In a bowl, add the juice from the pineapple chunks, BBQ sauce, garlic, and black pepper. Mix until well combined, then pour over the chicken and vegetables. Reserve the pineapple chunks for later.
Cook on high for 2 ½ to 3 ½ hours or on low for 4 to 5 hours.
Remove chicken and ¼ cup of sauce. Then, shred the chicken with two forks. Whisk cornstarch into reserved sauce. Add chicken, pineapple chunks, and cornstarch slurry to the crock pot. Toss until well coated and continue cooking for an additional 15 minutes.
Serve over rice and enjoy!
Notes
Substitute pineapple juice and fresh or frozen pineapple for canned pineapple chunks.
Shred the chicken with a stand mixer. Place the chicken in the mixing bowl and shred it on low using the paddle attachment. Just be sure not to over-shred it!