Rinse duck inside and out with cold running water and pat dry with paper towel, then set aside.

For brine, dry-roast spices in a very large saucepan over medium heat until fragrant (1 minutes). Add salt, sugar, green part of spring onions and 1 litre water and bring to the boil. Remove from heat. Add 4 litres cold water, stir to combine and set aside to cool. Once cool, submerge duck in brine, cover and refrigerate overnight to brine (12 hours).

For glaze, stir all ingredients in a saucepan over low heat until dissolved. Remove from heat; pour into a large deep roasting pan and cool to room temperature, then refrigerate to chill (2 hours).

Bring a wok or very large saucepan of water to the boil. Drain duck from brine, pat dry with paper towel. Carefully lower duck into boiling water to blanch (10 seconds), then immediately place into glaze, massaging and rubbing into skin, especially the breast, to coat. Stretch duck to remove any creases or wrinkles on the skin’s surface that have formed. Place the duck, breast-side up, on a large rack set over a large oven tray and refrigerate to dry out (2-3 days).

To roast duck, remove duck from refrigerator and bring to room temperature (2 hours).

Preheat oven to 200°C fan-forced. Place duck on a clean rack set over an oven tray. Roast duck, rotating oven tray occasionally, until crisp and deep golden. Juices should run clear when thigh is pierced with skewer (50 minutes-1 hour; if legs and wings start to burn, cover with foil). Set duck aside to rest (20 minutes).

Using kitchen scissors, cut through the breastbone of duck, then remove the backbone to give you two halves. Using a sharp knife or cleaver, cut the breast from the rib cage and thickly slice on an angle. For legs, cut up the leg bone, around the knuckle and thigh bone, twisting, if necessary, to release the meat from the joints in one large piece. Trim to a rectangle and thickly slice. Repeat with remaining duck half.

While duck is resting, steam pancake wrappers in a steamer basket set over a saucepan of simmering water until warmed through (3-4 minutes). Remove from heat and set aside, covered, until ready to serve.

Slice white parts of spring onion into julienne. Arrange duck, hoisin, pancakes, cucumber and spring onion on a serving platter to serve.