Chinese smoking (熏, xun) is a preservation and flavouring technique applied to meats, fish, and eggs — distinct from Western smoking in its use of unusual smoking agents including tea leaves, sugar, rice, and sawdust of specific woods, rather than exclusively wood smoke. The most famous application is tea-smoked duck (zhang cha ya, 樟茶鸭, Sichuan tea-and-camphor-wood-smoked duck) — a whole duck that is first cured with salt and spices, then smoked over a mixture of camphor wood chips, black tea leaves, and rice until a mahogany crust develops, then deep-fried to crisp the skin.
The wok-smoking technique (for home use): Line a wok with foil. Place the smoking mixture on the foil: 2 tbsp tea leaves (oolong, pu-erh, or black tea), 2 tbsp white sugar, 2 tbsp raw rice, optional spices (star anise, cinnamon). Place a wire rack above the smoking mixture. Place the food item on the rack. Cover the wok tightly with the lid. Seal any gaps with a damp towel. Heat over medium-high heat until the sugar and tea begin to smoke (3-5 minutes). Reduce to medium. Smoke for the required time. The sugar's role: Sugar added to the smoking mixture produces a sweeter, denser smoke and also contributes to the lacquer-like surface of the smoked item — the caramel compounds in the sugar deposit on the food's surface as the smoke condenses. Stepped preparation for professional tea-smoked duck: The full zhang cha ya requires 3 stages: dry cure (12-24 hours), smoking (2 hours), deep-frying (to crisp the smoked skin).
Fuchsia Dunlop, The Food of Sichuan (2019); Fuchsia Dunlop, Every Grain of Rice (2012)