In a large pot, add the whole chicken, salt, crushed ginger, garlic, and scallions. Add water to the pot until the chicken is completely submerged. Bring this to a boil, then turn it down and leave it to simmer, covered, for 15-20 minutes.
Meanwhile, prepare an ice bath in a separate deep pot. When the chicken is cooked, immediately transfer it to the ice bath to chill it down quickly. This helps the chicken skin tighten and you’ll get that jellied fat under the skin.
To make the marinade, reduce (boil off) the chicken poaching liquid until halved. Then, take two cups of this liquid and to this add the light soy sauce, Shaoxing wine, and sesame oil. Let the marinade cool down to room temperature, and pour onto a deep tray or container. In the same container, place the chicken breast-side down. Cover with whole container with plastic wrap, and leave in the fridge to marinate for 2-3 days. After the first day, flip the chicken over to get the chicken evenly marinated.
For the chilli oil, first, toast the dried chillies, chilli flakes, Sichuan peppercorns, star anise, bay leaf, cumin, five spice powder, and sesame seed in a pan. You’ll know when it’s done when the spices start to become really fragrant, and the pan starts to smoke just a little. Put the oil in a separate saucepan and heat it up to roughly 80°C. Then, dump all the spices into the oil. (Make sure your oil isn’t too hot! If the spices start to bubble and pop in the oil, you’ve gone overboard and it’ll likely burn.) Let the oil cool down to room temperature, then blend it in a blender until the spices are all pulverised. To the spiced oil, add the light soy sauce, vinegar, Shaoxing wine, sesame oil, sugar, and minced garlic, and you’ve got a spanking, spicy sichuan chilli sauce! The sauce can last for 2-3 days, up to a week (maybe two!) if you don’t add the garlic in.
On D-day, carve up the chicken (here’s a useful guide), drizzle on the sichuan chilli sauce, and garnish liberally with chopped scallions, cilantro, and sesame seeds. And boom, you've got yourself a Walter-White-worthy meal.