I use the following just last week...
Let the roast stand at room temperature for at least an hour. Preheat overn to 375 degrees. Rub meat well with salt and sprinkle with pepper. Place meat fat side up in a shallow roasting pan. DO NOT COVER, DO NOT ADD WATER. Put roast in oven , cook for just one hour. Turn off heat, but DO NOT OPEN OVEN DOOR AT ANY TIME UNTIL ready to serve.
Regardless of the length of time meat has been in over - 30 to 40 minutes before serving, turn oven on again and reset temp to 375 degrees and cook meat for those 30 to 40 minutes.
Now open oven door and remove roast to serving plate. Garnish with parsley. The meat will be very brown and crisp on the outside. Carve thin slices, you'll find it beautifully pink all the way though and juicey which is medium rare.