Place the ginger, onion, garlic and parsley in a food processor and process until a smooth paste forms. Add the wine, soy sauce, oil, and pepper and process to combine. Pour the marinade into a large zip-top bag, and add the steak. Lay on a plate and let marinate in the refrigerator, for at least 4 hours, ideally 6 hours, or even overnight (12 hours) if time permits, turning the steak a few times.
Set up the grill for direct grilling and preheat to high. When ready to cook, brush and oil the grill grate. Remove the steak from the marinade and drain well. Place the steak on the hot grate and grill until cooked to taste, 6 to 8 minutes per side for medium-rare, 2 minutes more per side for medium, rotating the steak 90 degrees after three minutes if a crosshatch of grill marks is desired. Alternately, place under a broiler, set about 3" below the heat source, for the same length of time.
Transfer the steak to a cutting board and let rest for 5 minutes. Using a sharp knife, carve it into broad thin slices, hold the knife blade at a 45 degree angle to the top of the meat. Serve at once.