1. Prepare the Meatballs:
In a medium bowl, combine ground beef, Shaoxing wine, soy sauce, chili flakes, brown sugar, garlic, and ginger. Mix until the mixture feels sticky and slightly bouncy. Add breadcrumbs, egg, and green onions, and mix until fully incorporated.

2. Shape the Meatballs:
Form the mixture into 24 heaping tablespoon-sized meatballs using your hands. For easier shaping, lightly grease your palms with oil to prevent sticking.

3. Prepare the Sauce and Slurry:
In a small bowl, mix the sauce ingredients until the sugar dissolves completely. In another small bowl, combine the slurry ingredients and mix well.

4. Cook the Meatballs:
Heat a large skillet over medium-high heat with 1 teaspoon of oil until hot. Add the meatballs, leaving space between them. Cook without moving them until the bottom browns. Flip 2-3 times until most sides are golden brown.

5. Add Sauce and Simmer:
Reduce heat to medium. Push the meatballs to one side of the pan and carefully remove excess fat with a spoon or paper towel. Pour the prepared sauce into the skillet. Stir the meatballs gently to coat evenly. Cook for 2 minutes.

6. Thicken the Sauce:
Reduce heat to medium-low. Stir the slurry to dissolve cornstarch completely, then swirl it into the pan. Stir immediately and let the sauce thicken. Remove from heat.

7. Garnish and Serve:
Garnish with sliced green onions. Serve hot over steamed rice for a complete meal.