Season the steaks with salt. Heat the oil in a skillet over medium-high heat. Sear the steaks 2 minutes per side, until nicely browned and still rare in the middle. (Cook longer if you like your steaks more well-done). Remove from the skillet and set aside. Drain all but 1 tsp. of fat from the skillet. Add shallots and garlic; cook 1 minute. Add port and reduce by half. Add the remaining ingredients and cook until slightly thickened. Return the steaks to the pan. Cook 2-3 minutes more, turning once, until the steaks are heated through, then serve.