Cut chicken into strips, then into cubes. Put into a medium bowl. Prepare the marinade. Add to chicken, mix well and let marinade for 30 minutes. While it is marinating mix all the sauce ingredients together.
When the meat has marinated, drain off the marinade. Heat a wok over high heat until smoke rises. Add the oil and swirl it around. Add the dried chilli, stir, then add the garlic and ginger and stir to release the aroma. Add the chicken and turn and toss for about a couple of minutes. Splash in the sherry around the side of the wok, stirring and tossing continuously. Add the spring onions and continue to stir for another 30 to 45 seconds. Add the well-stirred sauce to the wok. Continue to stir while it thickens - till you've been cooking for a total of 10 minutes.
Add the peanuts, stir to mix for a few times, then transfer to a warm serving plate. Serve with steamed rice.