Clean and de-stem the dried chilies, discarding any loose seeds. Simmer the chilies in a small pot of water for 10 minutes, then remove the pot from the heat but let the chilies sit and continue to soak until the water is just lukewarm. Drain the chilies and discard the seeds in the pot.
In a food processor, blend the chilies with the ginger and garlic to make a thick, chunky paste. (Alternatively, pound everything in a mortar and pestle). Set the chili paste aside.
Make the Braised Chicken
Heat 1 cup of oil in a wok to 390°F (200°C). Fry the chicken pieces in 2–3 batches until golden, turning occasionally if necessary to fry all sides, 4–5 minutes per batch. Drain each batch on paper towels.
Pour off half the oil and reserve for another use. Cool the remaining oil to 320°F (160°C), then add the ciba lajiao chili paste. Fry the paste over medium-low heat for 5 minutes, stirring, until it is fragrant and red. Add the doubanjiang, garlic and ginger and stir-fry everything for 1 minute.
Add the chicken back into the wok, then add 1–1½ cups of water (enough to mostly cover the chicken). Add the scallion, sweet wheat paste, dark soy sauce, sugar and Sichuan peppercorns. Cover the wok, leaving the lid slightly ajar, and simmer everything, stirring occasionally to prevent the dish from burning on the bottom, until the chicken is tender, 35–40 minutes.
Remove the wok lid and increase the heat to medium-high. Cook, stirring occasionally, until the sauce is reduced by half, about 5 minutes. Transfer the chicken to a serving bowl and garnish with the sliced scallion greens.
Notes
Note: Traditionally this dish mixes mild, aromatic chilies with a few spicier chilies. I prefer a mix of huaxi lajiao and wrinkled chilies. Adjust the balance to suit your heat tolerance.