In a large saucepan, whisk together cornstarch and pineapple juice until smooth. Add soy sauce, vinegar, water, and brown sugar, whisking to combine. Bring to a boil. Reduce heat to low and simmer, whisking constantly, just until thickened (about 3-5 minutes).
4 tablespoons cornstarch, 2 cups pineapple juice, ½ cup less-sodium soy sauce, ½ cup rice vinegar, ½ cup water, ¼ cup brown sugar
Pour sesame oil in the bottom of a slow cooker. Place meatballs in the slow cooker and pour sauce over top. Cover and cook on LOW for 2 hours.
2 tablespoons toasted sesame oil, 1 25 oz. bag frozen fully-cooked turkey or beef bite-sized meatballs
Stir in bell peppers and onion. Cook on LOW for 1 more hour, or until vegetables are tender and meatballs are heated through.
2 sweet bell peppers, 1 sweet onion
Serve over rice and garnish with sliced green onions and toasted sesame seeds, if desired.
White rice, brown rice, cauliflower rice, Sliced green onions, toasted sesame seeds