Mix together in equal amounts: red wine, olive oil, and vinegar to cover fillets for marinating. Add 2 to 3 tablespoons of Worchestershie and a teaspoon of black pepper. Marinate for 3 hours. Preheat a skillet to a frying temperature and preheat a grill to high. Remove fillets from marinade, melt a large pad of butter in the skillet and sear tuna steaks on each side for about ½ a minute. Remove steaks from skillet and place on grill. Rotate streaks about every 2-minutes. Cook steaks just long enough to ensure center is still rare to medium rare. (Depending on thickness, usually no more than 4-mintues total.) Remove from grill, let stand for 5-minutes and eat!