01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease.
02 - Combine ground chicken or turkey, breadcrumbs, egg, green onions, garlic, ginger, soy sauce, salt, and black pepper in a large bowl. Mix just until ingredients are incorporated.
03 - Roll mixture into 1-inch meatballs and arrange on prepared baking sheet.
04 - Bake for 15-18 minutes until cooked through and lightly golden.
05 - Whisk together pineapple juice, water, brown sugar, soy sauce, rice vinegar, and cornstarch in a small bowl until smooth.
06 - Heat vegetable oil in a large skillet over medium heat. Sauté red bell pepper for 2 minutes. Add pineapple chunks and cook another 2 minutes.
07 - Pour pineapple sauce mixture into the skillet. Bring to a simmer, stirring constantly until thickened, about 3-4 minutes.
08 - Add baked meatballs to the sauce and toss gently to coat. Simmer for 2-3 minutes to heat through. Serve hot, garnished with extra green onion or sesame seeds if desired.