Combine the sauce ingredients in a saucepan.

Bring to a boil over high heat, then reduce to low.

Cook until the mixture is thick and syrupy, about 25 minutes.

Let cool for 10 minutes, then strain through a fine sieve. Set aside or store in an airtight container until needed.

In a large bowl, mix all the meatball ingredients until you get a uniform paste.

Cover the bowl with plastic wrap and refrigerate for at least 15 minutes, up to overnight.

With wet hands, shape the mixture into slightly oval meatballs about 4 cm long. Thread 2 to 3 meatballs onto each skewer.

Heat a skillet over high heat. Once hot, oil it well and place the skewers a few centimetres apart. Cook until the first side is nicely browned and the meat releases easily from the grill, about 3–4 minutes.

Using tongs and a thin spatula, gently turn the meatballs and cook until well browned on the other side, about 3 minutes. Brush generously with sauce and cook 15–30 seconds more, until browned and caramelised in spots.

Transfer the skewers to a plate and brush again with the sauce until the meatballs are well glazed.

To serve, garnish with spring onions and white sesame seeds