- Drain the can of pineapple chunks and reserve the juice from the can in a separate bowl (1 cup pineapple juice is needed for the sauce). Set the pineapple chunks aside for later.  
- In a mixing bowl, whisk together the reserved pineapple juice and cornstarch until smooth.  - 1 cup pineapple juice, 3 tablespoons cornstarch 
- Add in the low-sodium soy sauce, tomato ketchup, light brown sugar, minced garlic, ground ginger, sesame oil, salt & pepper, and red pepper flakes (if using). Whisk to combine and set aside for later.  - 1/2 cup low-sodium soy sauce, 1/2 cup tomato ketchup, 3 tablespoons light brown sugar, 2 tablespoons minced garlic, 2 teaspoons ground ginger, 2 teaspoons sesame oil, ½ teaspoon kosher salt, ½ teaspoon black pepper, ¼ teaspoon red pepper flakes 
- Place the cubed chicken into the bottom of the slow cooker. Add the onion, red pepper chunks, and green pepper chunks over top the chicken.  - 2 pounds boneless, skinless chicken breast OR thighs, 1 sweet onion, 1 red bell pepper, 1 green bell pepper, 1 can (20 oz) pineapple chunks 
- Pour the sauce over the chicken and vegetables. Add the pineapple chunks on top. 
- Cover and cook on LOW heat for 6-7 hours. The chicken should be tender and cooked to a safe internal temperature of 165℉.  
- Serve hot over cooked white rice, brown rice, or noodles. Garnish with sesame seeds and sliced green onions. Enjoy! - sesame seeds & sliced green onions