Massage some salt into the chicken and let marinate for 15 minutes.
Place the ginger slices and garlic on the bottom of a dish, top with the chicken, then scatter with spring onions.
Steam the chicken for 30 minutes over high heat or until cooked through. Allow the chicken to cool a little before putting it into a resealable plastic bag. Drop the whole bag into ice water and allow the chicken to cool completely.
De-bone the chicken, then cut the meat evenly together with its attached skin. Shred the remaining chicken by hand.
Arrange the shredded chicken on the the bottom of a serving dish, then arrange the sliced chicken on top. Reheat the chicken to 250 degrees in the oven.
In a small bowl, make the sauce by mixing together the spring onions, oil, salt and finely chopped ginger. Serve with the chicken.