Suggested minimum sizes: 4 1/2 lbs for prime rib roasts, 3 lbs for loin roasts.
Remove roast from refrigerator 60 to 90 minutes prior to preparation.
Pat roast dry with kitchen towel, lightly coat with olive oil, sprinkle with salt and pepper.
Turn on the oven's top broiler.
Place roast fat side up on a rack in an open roasting pan.
Deeply insert meat thermometer.
Put roast about 3 inches below the broiler.
Broil for about 5 to 10 minutes, just until top fat begins to brown.
Turn the broiler element off.
Lower the oven rack so that the roast sits in the lower-middle part of the oven.
Set the oven to 275F.
Roast to 115F for a roast that will finish off rare, or 125F for a roast that will finish off medium-rare.
Remove roast from oven when desired temperature is reached.
Let the roast rest for 30 minutes before carving.
While the roast is resting the internal temperature of the roast will increase by 5 to 10 degrees.
A roast removed at 115F will have a finished temperature in the 120F to 125F range (rare); a roast removed at 125F will have a finished temperature in the 130F to 135F range (medium-rare).
Carve roast to desired thickness, serve 'au jus' or with pan gravy, and vegetables of choice.