Poaching is a cooking technique that makes the most of a fresh bird. My motheir - and many other Chinese cooks - poach the bird whole, but while this is great for the breast - leaving it moist, with a silky texture, it means the leg meat is still pink, which many people find unpleasant.
To get around this, I remove the legs - thigh and drumstick - from the rest of the bird, and leave them to cook for a little longer in the poaching liquid. After the chicken is cooked, it's plunged into a bowl of iced water, which tightens the skin and firms up the meat (this only works for fresh birds). The poaching liquid can be reduced then used as a light chicken stock.
Kou shui ji is a Sichuan dish that translates to saliva chicken or mouth-watering chicken, because it's so delicious it gets your salivary glands going.
Sever the neck from the chicken, cutting as close to the body as possible. Chop off and discard the head. Cut off the wing tips and the feet. Sprinkle salt liberally over the skin and into the cavity of the chicken, rub it in and leave for about 10 minutes. Thoroughly rinse the chicken inside and out.
Put the chicken in a large pot, add enough water to cover by 2.5cm (1in) then remove the bird (this helps you measure the correct amount of water). Remove the legs (thighs and drumsticks) from the rest of the bird, cutting between the joint where the thigh meets the carcass. Leave the legs whole.
Put the spring onions and ginger in the pot along with the wing tips, feet and neck. Bring to the boil over a high flame, then add the legs and body. Let the water come to the boil again then turn off the heat, cover the pan with the lid and poach the chicken for 20 to 25 minutes. Turn the chicken pieces over in the pan, and heat over a high flame until the water boils. Turn off the flame, cover the pan with the lid and poach the chicken for another 20 to 25 minutes.
Take the chicken body from the poaching liquid and place it immediately in a large bowl of heavily iced water. Heat the pan over a high flame until the water boils. Turn off the flame, cover the pan with the lid and poach the legs for another 10 to 20 minutes. Remove the legs from the water and put them into the bowl of iced water.
When the chicken pieces are cool, remove them from the water and pat them dry with paper towels before rubbing the sesame oil over the skin and the meat.
Make the sauce. In a small unoiled skillet, toast the Sichuan peppercorns over a low flame, stirring constantly. Remove and discard as many of the black seeds as possible. Put the peppercorns husks in a mortar and grind them as finely as possible (or use a spice grinder).
Finely mince the garlic and ginger and put them in a mixing bowl. Add the regular soy sauce, light sauce, vinegar and sugar and stir together. Add as much of the ground Sichuan peppercorns as you like, then stir in the sesame oil. Add chilli oil to taste.
Put the chicken body breast side-up on a cutting board. Carefully slice off the breasts, cutting as close to the bone as possible. Slice the breast meat about 1cm (7/16 in) thick, then place the pieces skin side-up on a shallow serving dish
Remove the wings from the carcass and separate them into drumette and middle joint before placing them on the serving dish.
Put the chicken legs skin-side down on the cutting board. Use a sharp knife to cut the drumstick and thigh along the length of the bone. Pull the bones from the meat, then slice the drumstick and thigh meat about 1cm (7/16 in) thick. Place the meat skin side-up on the serving dish.
Take a scrap of meat from the carcass, dip it in the sauce and taste, and if necessary, adjust the seasonings. Pour the sauce over the chicken in the serving dish.
Cut the Chinese celery into 2.5cm (1 inch) lengths and arrange over the chicken. Scatter the sesame seeds and peanuts over the ingredients. Add fresh coriander leaves just before serving.