Preheat oven to 400°F (200°C).
In a mixing bowl, combine ground beef, breadcrumbs, egg, garlic, onion, salt, and pepper. Mix well.
Form mixture into meatballs and place on a baking sheet.
Bake for 15-20 minutes, until cooked through.
In a saucepan, combine pineapple juice, brown sugar, and soy sauce. Bring to a boil.
Add cornstarch mixture to the saucepan and stir until thickened.
Add cooked meatballs to the sauce and simmer for 5 minutes.
Serve hot with rice or noodles.