Clean and halve the pig's kidney. Remove any membrane and make light criss-cross cuts on the surface. Soak pig's kidney in salted water for 25-30 minutes, then rinse under running tap water. Bring a saucepan of water to a rolling boil and blanch the pig's kidney. Remove and drain well.
Heat sesame oil and fry ginger shreds until fragrant and golden. Add pig's kidney and light soy sauce and pepper. Stir-fry briskly for a while. Add ginger wine and sugar to taste, and cook until sauce is fragrant. Dish out and serve hot.