To marinate the chicken, pat the chicken dry, then rub the salt all over, including inside the cavity. Combine the ginger purée with the Shaoxing wine, then rub it over the chicken inside and out, and let it sit for 20 minutes.
To make the ginger scallion oil, in a bowl, combine the scallions, ginger, and salt. In a pan over low heat, add the cooking oil and shallots, and fry until golden, then remove the shallots. Heat the oil until smoking, then carefully pour it over the scallion and ginger mixture and mix well.
To steam the chicken, brush the chicken skin with cooking oil, then line a steamer with the sliced ginger and place the chicken breast-side down. Steam over medium heat for about 40 minutes, until the internal temperature reaches 165°F.
To serve, let the chicken cool slightly, then chop or shred into pieces and serve with the ginger scallion oil.