Remove the roast from refrigerator 1 hour before cooking to reach room temperature. Using a sharp knife, pierce meat about 1/2-inch deep and insert slivers of garlic in each hole, pushing all the way in.
Lightly cover beef with olive oil and season generously with salt, pepper and rosemary.
Place an oven safe meat thermometer all the way into the center of the meat. Place the roast in a roasting pan with a rack (you can cook without a rack if you don't have one).
Preheat oven to 350° F. When the oven reaches 350° F, put roast in the oven.
Roast until the thermometer reads 130° for rare, 135° for medium rare, 140° for medium, and 155° for well done. Due to carryover cooking, when the center of a roast comes within 10 degrees of the target, it’s time to take it off the heat. The temperature will rise an additional 5-7° degrees as it rests after being removed from the oven.
Remove the roast from the oven and let it rest 15-20 minutes before you cut it so that the juices distributed evenly.
