Remove fat from inside body cavity of duck; trim excess fat from tail, neck and leg areas.
Pat duck dry inside and out with paper toweling.
Cut shallow slits at 1 inch intervals through skin into fat with a small sharp knife.
Stir scallions, ginger, salt, black pepper, Sichuan peppercorns, and tangerine zest in small bowl until combined.
Rub spice mixture thoroughly into inside and outside of duck.
Wrap duck securely in double thickness of heavy-duty aluminum foil; refrigerate 2 days.
Unwrap duck; place on plate in large bamboo or metal Chinese steamer tier.
Steam, covered, over 2 inch3 es of boiling water in wok or bottom of metal steamer until juice runs clear, not pink, when thigh is pierced with tip of knife, about 45 minutes.
Remove duck from steamer to wire rack; cool to room temperature.
Line bottom of wok with double thickness of heavy-duty aluminum foil.
Combine tea leaves, rice, and wood chips.
Pour into wok.
Place three wooden chopsticks in criss-cross triangle pattern over bottom of wok to act as support for duck.
Heat wok over medium-high heat until mixture on bottom begins to smoke **.
Wipe spice mixture from outside of duck; place duck on chopstick rack in wok.
Cover wok tightly; smoke duck until skin is golden brown.
About 30 minutes.
** Heat oven to 450.
Place smoked duck on rack in roasting pan; roast until brown, about 10 minutes.
Remove duck from oven; allow to cool to room temperature if not serving hot.
Cut duck into serving pieces and serve hot or at room temperature, or remove meat from bones and slice thin, removing any fatty skin, and serve cold or at room temperature.
Garnish with tangerine sections and coriander sprigs, if desired.
*To roast and grind brown Sichuan peppercorns: Heat peppercorns in small heavy skillet over low heat until fragrant and dark brown, about 5 minutes, shaking pan occasionally; do not allow peppercorns to burn.
Remove and let cool.
Grind coarsely, using mortar and pestal.
**Do not attempt this recipe unless range is close to ventilation system.
Temperature under wok should be regulated during entire smoking time to ensure a thin steady stream of smoke.
**To check duck for doneness, starting about 20 minutes after duck begins to smoke, take covered wok outside or hold directly under exhaust fan; lift cover slightly.