Mix the chicken pieces, 1 tbsp soy sauce, 1 tbsp rice wine, and all of the cornflour together in a bowl. Cover and transfer to the fridge to marinate for at least 30 mins.
In another bowl, stir together the remaining soy sauce and rice wine, the vinegar, sugar and chilli bean paste until the mixture is smooth.
Slice the green parts of the spring onions lengthways into thin strips. Trim and chop the white ends into thin slices, then put in a small bowl with the ginger and garlic.
Heat the groundnut oil in a wok set over a high heat, then add the chillies and ground peppercorns and stir-fry until the chillies have darkened slightly (be careful not to burn them). Add the marinated chicken pieces and continue to stir-fry for 5-8 mins, or until the chicken has browned. Add the spring onion and ginger mixture and stir-fry until the meat is just cooked through. Add the vinegar mixture and toss to combine, then stir through the green parts of the spring onions, the sesame oil and peanuts. Serve with boiled rice.