Prep ingredients for the stir-fry. Tear or snip chilies into pieces and shake out the seeds. Leave smaller chilies whole. Mince the ginger and garlic and cut the scallions. Mix sauce ingredients together in a measuring cup or small bowl: vinegar, chicken stock, sugar, light soy sauce, wine, cornstarch and salt.
Cut chicken into small cubes of ½ inch, and no larger. Marinate chicken cubes with wine, soy sauce, cornstarch and salt while you fry the nuts.
Heat wok until hot and add 2 tablespoons caiziyou (or other cooking oil). Immediately turn heat to medium and add nuts to cold oil. Slowly stir-fry until nuts are toasty brown all over. Turn down heat if they are browning too quickly, and watch closely so they don't burn. Remove from wok and drain on paper towel. They will firm up and become crunchy when cool. (Don't be tempted to substitute roasted nuts or skip this step; it makes all the difference.)
Clean wok and heat over a high flame until very hot (which keeps the chicken from sticking). Add ¼ cup oil, swirl around the pan and add the chicken cubes. Spread the chicken out around the wok, and let the pieces sear on one side. Flip the chicken and let sear on the other side. Stir-fry until chicken is just cooked through. Remove chicken from wok and hold.
Clean wok and return to heat. When wok is hot, add 2 tablespoons fresh oil and heat briefly on a medium flame. Add chilies and Sichuan peppercorns and stir-fry quickly, toasting but not burning them. Add the scallion whites, ginger and garlic and stir-fry until fragrant.
Add the chicken cubes and the sauce and stir-fry to mix. As the sauce thickens, add the scallions greens and fried nuts and cook briefly until all ingredients are well combined.
