Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a mixing bowl, combine the ground beef, breadcrumbs, Parmesan cheese, green onions, egg, minced garlic, salt, and pepper. Mix until well combined.
Shape the mixture into 20 small meatballs, about 1 inch in diameter, and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for 15 minutes or until cooked through (internal temperature should reach 160°F/70°C).
While the meatballs are baking, prepare the honey garlic sauce. In a frying pan over medium heat, combine honey, soy sauce, minced garlic, and apple cider vinegar. Bring to a simmer.
If you prefer a thicker sauce, mix cornstarch with water in a small bowl and add to the sauce, stirring until it thickens slightly. Remove from heat.
Once the meatballs are done, transfer them to the frying pan with the honey garlic sauce. Toss to coat the meatballs evenly in the sauce.
Serve the honey garlic meatballs over rice or enjoy them as they are. Garnish with additional green onions if desired.