01 - Place chicken thighs or breasts in the bottom of the slow cooker, ensuring even distribution for consistent cooking.
02 - Whisk together pineapple juice, soy sauce, brown sugar, ketchup, rice vinegar, garlic, and ginger in a medium bowl until sugar dissolves completely.
03 - Pour the sauce mixture over the chicken, then arrange onions, bell peppers, and pineapple chunks evenly on top.
04 - Cover and cook on LOW setting for 4-5 hours until chicken reaches internal temperature of 165°F and becomes tender.
05 - Transfer cooked chicken and vegetables to a serving platter, covering loosely with foil to maintain warmth.
06 - Create slurry by mixing cornstarch and water until smooth. Pour cooking liquid into saucepan, bring to simmer over medium heat, then whisk in slurry. Cook 2-3 minutes until sauce reaches desired consistency.
07 - Pour thickened sauce over chicken and vegetables. Garnish with sliced green onions and sesame seeds. Serve immediately with steamed rice.