If you choose to brown the chicken parts, heat the oil in a large skillet over medium-high heat. Brown chicken on all sides. Place in crock pot. If not browning the parts or you are using cut up chicken breast (see NOTES) place the raw chicken in the slow cooker.
Mix sauce ingredients in a small bowl and pour over chicken. Cover and cook on low 3-5 hours or high 2-4 hours.
Add the pineapple chunks and the bell peppers and cook an additional 2 hours on low, 1 hour on high, or until chicken is cooked through.
To thicken sauce, remove chicken parts (if you used the cut-up breasts it’s not necessary to remove it). Mix he cornstarch and water in a small bowl. Turn the cooker to HIGH and stir in the cornstarch/water mixture. Stir until juice begins to thicken. Add the chicken parts back to the pot and cook for 15 additional minutes.
Serve over rice.
You can use cut up boneless skinless breasts. Reduce total cooking time to 2-3 hours on high or 3-5 hours low--COOKING TIMES ARE APPROXIMATE. SOME COOKERS COOK HOTTER AND FASTER. LET YOUR OWN EXPERIENCE WITH YOUR COOKER BE YOUR GUIDE.