1. Combine the potato flour or cornflour with the cold water in a bowl and mix well. Add the chicken pieces and turn to coat, then season with five-spice powder.
2. Heat a wok over a high heat and add the groundnut oil. When the oil starts to smoke, add the Sichuan peppercorns, chilli bean paste and ground red chilli and stir-fry for 30 seconds. Add the chicken and leave to settle for 30 seconds, then add a dash of rice wine or sherry. Toss all the ingredients well and cook for 3-4 minutes until the chicken has turned virtually opaque.
3. Add the cashew nuts and cook for another minute, then add the spring onions, toss well and cook for another minute. Season to taste with soy sauce and add a squeeze of lime juice. Transfer to serving plates and serve with egg-fried rice or plain rice.
Chicken thigh meat is delicious and tender, and it's cheaper than breast too. To de-bone it, just use a small sharp knife and cut as close to the bone as possible, or get your butcher to do it for you.