Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper or lightly grease it.
In a mixing bowl, combine the ground meat, breadcrumbs, milk, egg, minced garlic, chopped green onions, soy sauce, salt, and pepper. Mix until well combined.
Shape the meat mixture into small meatballs, about 1 inch in diameter, and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for 20-25 minutes, or until they are cooked through and browned on the outside.
While the meatballs are baking, prepare the teriyaki sauce. In a saucepan, combine the soy sauce, water, brown sugar, honey, sesame oil, grated ginger, and minced garlic. Stir to combine.
Bring the sauce to a simmer over medium heat. If you prefer a thicker sauce, you can mix a tablespoon of cornstarch with a tablespoon of water and add it to the sauce, stirring until it thickens.
Once the meatballs are cooked, remove them from the oven and transfer them to a serving dish.
Pour the teriyaki sauce over the meatballs, coating them evenly.
Garnish with sesame seeds and sliced green onions, if desired.
Serve the teriyaki meatballs hot as an appetizer, main course, or party snack. Enjoy!