How to Make It
Heat the oil in a small saucepan. Add the Sichuan peppercorns and cook over moderate heat until darkened, about 4 minutes. Strain the oil into a small bowl.
Heat 2 tablespoons of the strained oil in the saucepan. Add the chiles, garlic and ginger and cook, stirring, over moderate heat until the chiles darken, about 3 minutes. Add the black beans and cook for 30 seconds. Add the chicken stock and boil over high heat until reduced by half, about 3 minutes. Season lightly with salt.
In a large skillet, heat the remaining strained oil until shimmering. Season the meat with salt. Add half of the meat in a single layer and cook over high heat until browned and medium-rare, about 1 minute per side. Transfer to a platter and repeat with the remaining meat. Reheat the sauce and add the scallions. Pour the sauce over the meat, scatter the cilantro leaves on top and serve.