01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - In a large bowl, combine ground chicken, breadcrumbs, egg, green onions, garlic, soy sauce, ginger, black pepper, and salt. Mix gently until just combined, being careful not to overwork the meat.
03 - Roll the mixture into uniform 1-inch meatballs and arrange them on the prepared baking sheet with even spacing.
04 - Bake for 18-20 minutes until the meatballs are cooked through to an internal temperature of 165°F and lightly golden on the outside.
05 - While the meatballs bake, combine pineapple juice, soy sauce, rice vinegar, brown sugar, and ketchup in a saucepan over medium heat. Bring to a gentle simmer, stirring occasionally.
06 - In a small bowl, dissolve cornstarch in water to create a slurry. Whisk the slurry into the simmering sauce and cook for 2-3 minutes, stirring constantly, until the sauce thickens to a glossy glaze consistency.
07 - Stir the drained pineapple chunks into the thickened sauce and simmer for an additional 2 minutes to warm through.
08 - Transfer the baked meatballs into the saucepan, tossing gently to coat evenly. Continue cooking for 2-3 minutes over low heat until the meatballs are thoroughly glazed and heated through.
09 - Serve hot, garnished with fresh cilantro or parsley, alongside steamed rice or noodles if desired.