Heat a platter or plates in a slow oven. On the stove, heat a large cast iron skillet over high heat till very hot. Add olive oil, then steaks, and sauté meat till desired doneness (2 minutes on each side for rare, 3 minutes for medium-rare). Transfer steaks to oven and discard excess fat from pan. Sauté shallots in pan for 20 seconds, then pour in wine and diluted stock, stirring to incorporate all browned cooking bits into liquid. Boil liquid till reduced to 2-3 tablespoons. Off the heat, whisk in butter a tablespoon at a time. If desired, cut the steak into slices across the grain of the meat. Spoon sauce onto meat and serve.