In a medium-size bowl, combine ground beef, Shaoxing wine, soy sauce, chili flakes, brown sugar, garlic, and ginger. Beat the mixture for about 2 minutes until it feels sticky and bouncy. Add breadcrumbs, egg, and green onions. Mix until fully incorporated.

Form the mixture into 24 meatballs, about a heaping tablespoon each. Grease your palms with a bit of oil to prevent sticking. Roll each portion between your palms until smooth and round.

In a small bowl, mix together all sauce ingredients (brown sugar, soy sauce, water, garlic, and ginger), stirring until the sugar dissolves. In another small bowl, combine cornstarch and water for the slurry.

Heat a large skillet over medium-high heat with canola oil. Once hot, add the meatballs with space between each one. Cook without moving for 3 minutes until bottoms turn golden brown. Flip 2-3 times until most sides are browned, about 5-7 minutes total.

Reduce heat to medium. Push meatballs to one side of the pan. Use paper towels attached to tongs to remove excess fat from the pan.

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

Turn heat to medium-low. Stir the slurry again to dissolve cornstarch completely, then swirl into the pan. Stir immediately and cook for 1-2 minutes until sauce thickens and becomes glossy. Remove from heat.

Garnish with sliced green onions and serve hot over steamed rice.