Heat a frying pan over high heat. Add the Szechuan peppercorns, reduce heat to medium and dry fry for about 4 minutes, until fragrant. Transfer to a mortar and pestle or a spice blender and crush to a fine powder. Place the chicken thighs in a large bowl, sprinkle over the Szechuan peppercorns and stir to combine.
Pour 1 tablespoon of macadamia oil into a wok over high heat. Add the chicken and fry, tossing occasionally for 5 to 7 minutes, or until golden and cooked through. Remove from the pan and set aside.
Heat the remaining 2 teaspoons of oil in the wok, add the garlic and ginger and fry, tossing continuously for 2 minutes, or until lightly golden. Add the spring onions and stir to combine. Remove and set aside with the chicken.
Combine the soy sauce, vinegar, sherry and honey in a small bowl. Heat the wok over high heat and pour the mixture in. Bring to the boil, reduce heat and simmer for 1 minute. Stir in the chicken and garlic mixture and cook for 1 minute to heat through. Place on a serving platter and serve sprinkled with macadamia topping and coriander leaves and stems.