Wash the chicken inside and out and pat dry with paper towels. Rub inside and out with salt, then put in the fridge and let stand overnight.
Place the chicken in a steamer or colander and suspend that in a stockpot. Pour in water to within a couple of centimetres of the bottom of the steamer. Cover and steam the chicken over rapidly boiling water 45 minutes (add water if necessary).
Heat the brown sugar in a large saucepan lined with foil. Place a round rack in the saucepan and add the chicken. Cover with a lid to prevent smoke from escaping. Smoke the chicken 10 minutes over medium heat.
Turn off heat and let stand 5 minutes. Rub the chicken with sesame oil and cut into small pieces.