Crispy Sichuan-Chili Chicken

La zi ji (which translates from the Mandarin as chicken with chilies) is a traditional Sichuan dish that gets some of its kick from Sichuan peppercorns, which lend a citrusy, floral note followed by tingling—but not eye-watering—heat. To toast the Sichuan peppercorns, heat them in a small skillet over medium and cook, shaking the pan frequently, until fragrant, about 2 minutes. Transfer to a bowl and let cool, then finely grind in a spice grinder. To remove any large, fibrous bits, sift the ground pepper through a mesh strainer. For additional heat, we made our own chili oil from Sichuan chili flakes, more peppercorns and whole dried red Sichuan chilies. Tailor the heat of this dish by using more or less of the chili oil.