Step 1

In a large (at least 8-quart) pot, combine 4½ quarts water, the scallion whites, ginger and 1 tablespoon salt; bring to a boil over high. Slowly lower the chicken into the water breast side up, letting the liquid flow into the cavity. If the chicken floats and isn’t fully submerged, weigh it down with a heat-proof plate. Return the liquid to a boil, then reduce the heat to medium and cook, uncovered and at a bare simmer, for 30 minutes, flipping the chicken breast side down after 15 minutes. Turn off the heat, cover the pot and let stand for 30 minutes.

Step 2

Transfer the chicken to a large plate and cool for 20 minutes. Reserve 3 tablespoons of the poaching liquid for finishing the dish; discard the remainder or strain and reserve for another use. Refrigerate the chicken, uncovered, until chilled, 1½ to 2 hours.

Step 3

Meanwhile, in a small saucepan over medium, toast the sesame seeds, stirring often, until fragrant and golden brown, about 3 minutes. Transfer to a small plate; set aside. In the same pan over medium, toast the Sichuan peppercorns, stirring, until fragrant, about 1 minute. Transfer to a mortar and pestle or spice grinder, cool slightly, then grind until fine; set aside.

Step 4

In the same pan, combine the neutral oil and peanuts. Cook over medium, stirring occasionally, until the nuts are golden brown, 4 to 6 minutes. Using a slotted spoon, transfer to a paper towel-lined plate and cool. Discard the oil. Roughly chop the peanuts; set aside.

Step 5

In a small bowl, combine the chili oil, sesame paste, soy sauce, sesame oil, vinegar, sugar, Sichuan pepper and 2 tablespoons of the reserved chicken poaching liquid. Whisk until smooth and creamy; set aside.

Step 6

Shred the chilled chicken, pulling the meat into large bite-size pieces and discarding the skin and bones. Transfer the meat to a platter. Drizzle with the remaining 1 tablespoon reserved poaching liquid and toss. Drizzle the sesame sauce over the chicken, then sprinkle with the peanuts, scallion greens and sesame seeds. If desired, drizzle with additional chili oil.