In a large, deep skillet, heat the oil. Add the ground pork and cook over high heat, breaking up the meat, until it is browned, about 5 minutes. With a slotted spoon, transfer the cooked pork to a plate. Add the chiles, onion, ginger, garlic and black beans to the skillet and cook over moderately high heat, stirring, until softened, about 5 minutes. Add the hoisin sauce and cook, stirring, for 1 minute. Add the rice wine and simmer until reduced by half, about 2 minutes. Add the stock and pork and simmer until thickened, about 4 minutes. Add the scallion and season with salt and pepper.