Heat oven to 200°C fan (or 210°C conventional). Line a baking tray with baking paper.
Prepare the glaze: In a small bowl, mix the cornstarch with the cold water and set aside. In a small saucepan, combine the soy sauce, hoisin sauce, honey, garlic powder, ginger powder, and water. Bring to a boil, then reduce to a gentle simmer for 30–45 seconds. Whisk in the cornstarch mixture and simmer for a further 30–60 seconds, stirring continuously, until the glaze thickens and becomes glossy. Remove from the heat and set aside.
In a large bowl, combine the panko breadcrumbs and milk (or water). Mix and allow to soak for 1–2 minutes until fully hydrated.
Mix the meatballs: Add the pork mince, egg, breadcrumbs, garlic powder, ginger powder, soy sauce, rice wine vinegar, salt, and pepper. Mix until the mixture is well combined and slightly sticky, but do not overwork.
Shape the mixture into small-to-medium meatballs and place them on the prepared tray, leaving a little space between each one. Bake for 12–14 minutes, turning once halfway through, until lightly browned and just cooked through.
Glaze the meatballs: Return the glaze to a pan over medium heat. Once bubbling, add the hot meatballs and toss gently for 30–60 seconds until evenly coated and the glaze thickens and clings to the meatballs.
To serve: Transfer to a serving dish, sprinkle with sesame seeds, and serve hot with rice, noodles, or a crisp Asian slaw (recipe here).