Preheat your oven to 200°C (400°F). In a bowl, combine ground beef, breadcrumbs, beaten egg, soy sauce, Shaoxing wine, garlic, ginger, green onions, salt, and pepper. Mix gently to avoid overworking the meat.
Shape into 2.5 cm (1-inch) meatballs and place them on a parchment-lined baking sheet. Bake for 10-12 minutes until golden brown and cooked through.
Heat a skillet over medium heat. Add soy sauce, brown sugar, water, hoisin sauce, oyster sauce, ginger, garlic, and red pepper flakes. Bring to a gentle simmer.
In a small bowl, mix cornstarch with water to create a slurry. Gradually add the slurry to the sauce while stirring. Cook until the sauce thickens, about 2-3 minutes.
Add the cooked meatballs to the sauce and gently toss until evenly coated.
Garnish with green onions and sesame seeds. Serve hot, either as an appetizer, over steamed rice, or with rice vermicelli for a light and flavorful meal.
