Heat wok over high heat, 45 seconds to 1 minute. Lower heat and add all the ingredients. Dry-roast, stirring, until the five-spice powder turns black. Remove and strain off the peppercorns; discard them. Place the spice salt in a small dish and serve with the chicken.
The spice salt can be made 2 or 3 days in advance, then, when cool, placed in a tightly sealed jar, unrefrigerated.