Place all ingredients in wok over medium heat, swirling wok, for 2 to 3 minutes. Let cool.
To make ground toasted Szechuan peppercorns, if not readily available:
Heat a dry wok over moderate heat and pour in 1 tbsp. whole Szechuan peppercorns. Cook, stirring constantly, about 1 minute, or until they release their fragrance. Grind to a fine powder in a mortar or blender, strain out any large husks.