In a medium-size bowl combine ground beef, Shaoxing wine, soy sauce, chili flakes, brown sugar, garlic, and ginger. Beat until the meat starts to feel sticky and bouncy. Add the breadcrumbs, egg, and green onions. Mix until fully incorporated.

Form the mixture into 24 heaping tablespoon-sized meatballs using your hands. For easy forming, grease your palm with a bit of oil to prevent the meat from sticking too much.

Add the sauce ingredients to a small bowl. Mix to dissolve the sugar completely.

Combine the slurry ingredients in a small bowl and mix well.

Heat a large skillet over medium-high heat with 1 teaspoon of oil until hot. Add the meatballs with some space in between. Cook without touching until the bottom turns brown. Flip the meatballs 2 to 3 times, until most of the sides turn golden brown.

Turn to medium heat. Move the browned meatballs to one side of the pan. Use a spoon or a few layers of kitchen paper towel attached to a pair of tongs to remove some of the excess fat that collects in the pan.

Pour the sauce into the pan. Cook for 2 minutes while stirring the meatballs to coat them in the sauce evenly.

Turn to medium-low heat. Stir the slurry again to dissolve the cornstarch completely and swirl into the pan. Stir immediately and let cook until the sauce thickens. Remove the pan from the heat.

Garnish with sliced green onions.

Serve hot over steamed rice as a main dish.