Crockpot Pineapple BBQ Chicken

1 medium onion, diced
20 oz. can pineapple chunks, reserve juice
1/2 t. red pepper flakes
2-3 lbs boneless skinless chicken breasts or tenderloins
1/4 c. BBQ seasoning, your choice
2 T. teriyaki sauce
1 T. olive oil
1 1/2 c. thick BBQ sauce
6 oz. can tomato paste

Line crockpot. Place onion and pineapple in bottom. Sprinkle with red pepper flakes. Rub chicken on all sides with seasoning. Place on top of pineapple. Drizzle with teriyaki sauce, oil, and garlic. Combine pineapple juice with BBQ sauce and drizzle over chicken. Cover. Cook on low for 6 hours. Uncover. Remove chicken to platter and keep warm. Thicken sauce in crockpot with tomato paste. Return chicken to crockpot. Serve with/over rice and green beans. Drizzle with additional sauce. Two photos below. One with chicken over the rice, and the other with the sauce over the rice and chicken beside it. Either way is good!