In a medium bowl, whisk together the pineapple chunks (with juice), low-sodium soy sauce, rice vinegar, ketchup, brown sugar, minced garlic, and ground ginger.
Place the bite-sized chicken pieces at the bottom of your Crockpot. Pour the sauce mixture over the chicken, ensuring each piece is well coated.
Sprinkle the finely chopped onion and diced bell peppers on top of the chicken and sauce.
Cover the Crockpot and set it to cook on low for about 6-8 hours or high for 3-4 hours.
Once the cooking time is up, mix the cornstarch with a couple of tablespoons of water to create a slurry. Stir this into the Crockpot and let it cook on high for an additional 15-30 minutes until the sauce thickens.
Spoon the Crockpot Hawaiian Chicken onto plates or over a bed of rice. Garnish with chopped green onions and a sprinkle of sesame seeds.
