Preheat the oven to 150°C. Oil a deep roasting tin and lay in the onion slices.
Fill the chicken cavity filled with garlic, ginger and anise, then put it on top of the onion slices.
Sprinkle with 1 Tbsp sugar, season with pepper, then drizzle with 2 Tbsp of soy sauce.
Pour over the stock and rice wine, then sprinkle with the remaining sugar and pour over the remaining soy sauce.
Cover the tin with aluminum foil (or a lid) and bake the chicken for 2 hours.
Take the chicken out of the oven and turn up the oven temperature to 180°C.
Baste the chicken with the cooking juices then pour over the sesame oil. Bake for another 30 minutes (without any cover).
When it's cooked through , take it out of the oven and let it rest for 10 minutes.
Carve and serve with the cooking juices, onion slices and some coriander scattered on top.