Marinate the duck breast with five-spice powder, ginger root, scallions, salt and pepper for at least 6 hours or overnight, covered and refrigerated.
Preheat oven to 400 degrees. Heat skillet on moderately high heat, do not add any oil. Sear duck breast skin side down, brown both sides. Transfer duck to oven proof plate and cook the duck in the oven for 10 minutes for medium rare. Pour off grease from the skillet, add plum wine, add duck stock, season with salt and pepper and reduce the sauce to 1 cup. Then incorporate the butter into the sauce and set aside and keep warm. Remove duck from oven let it sit for 5 minutes before slicing.