Preheat your oven to 500°F (260°C).

In a large mixing bowl, combine all meatball ingredients: ground chicken, panko breadcrumbs, crushed pineapple, milk, reduced-sodium soy sauce, green onions, minced garlic, fresh ginger, black pepper, and brown sugar.

Scoop out portions of the meat mixture and roll them into balls about the size of golf balls, roughly 1 to 1.5 inches in diameter. Aim for approximately 21 meatballs.

Place each meatball on the prepared baking sheet, spaced evenly for proper heat circulation.

Bake the meatballs for about 15 minutes, or until golden brown and cooked to an internal temperature of 165°F (75°C).

Prepare the teriyaki sauce by combining reduced-sodium soy sauce, brown sugar, reserved pineapple juice, minced garlic, fresh ginger, and water in a saucepan over medium heat.

Mix cornstarch with a bit of water until smooth, then add it to the saucepan to thicken the sauce while stirring continuously.

Once baked, transfer meatballs to a serving bowl and pour the teriyaki sauce over them, tossing gently to coat.

Serve hot over rice or alongside steamed vegetables.