Put the liver in the freezer until it firms up, then slice it thinly. Mix the Chinese five-spice powder, garlic and rice wine in a bowl, then add the liver. Mix well, then leave to marinate for 25 minutes.
Heat the oil in a wok, add the ginger and stir-fry until crisp and golden brown. Add the liver and its marinade, the oyster sauce, soy sauce, pepper and sesa