In a medium sized bowl mix together all the meatball ingredients. Using wet hands, shape the mix into 16 equal sized balls. Shallow fry in a large saucepan with a little sesame oil until browned and cooked through.
Add all of the sauce ingredients apart from the cornflour to a small saucepan and simmer for 3-4 minutes, or until sticky and reduced. In a small bowl, whisk the cornflower/cornstarch with 1 teaspoon cold water, then add to the pan. Simmer for a further minute - the sauce should be thicker now.
Remove from the heat and pour over the meatballs, tossing them in the sauce to coat evenly.
Transfer to a serving dish or bowl, then scatter over the sesame seeds and spring onion/scallion and serve with cocktail sticks or toothpicks for easy eating.