Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or tin foil.
Mix together the ground beef, breadcrumbs, egg, green onions, Shaoxing wine, 1 tablespoon of soy sauce, 1/2 of the garlic and 1/2 of the ginger. Form 20 meatballs.
Set the meatballs, spaced out, on the baking sheet and cook for 20 minutes, turning the meatballs over halfway through. When done, transfer to a bowl.
Mix 1/4 cup soy sauce, 1/4 cup brown sugar, the water, and the remaining garlic and ginger in a sauce pan. Heat over medium until bubbling. Add the cornstarch slurry and stir until thickened. Remove from heat and pour over the meatballs in the bowl. Toss to coat.
You can skewer the meatballs, or serve them all in a bowl. Serve with sesame seeds and green onions as garnish.