To make the marinade, mix together the ginger, spring onions, sea salt, soy sauce and shaoxing. Add the chicken and toss together. Leave for 15 minutes, then drain.
Heat the oil in a wok or deep-fryer until just smoking (180°C/350°F), and deep-fry the chicken in batches until golden, then drain on paper towel. Pour the oil from the wok and wipe clean.
Reheat the wok with