Combine all ingredients, except garlic and rosemary, and blend well.

Place roast in an oven-proof baking dish.

Cover roast with the marinade and place in the refrigerator for 24 hours, turning every a few times, ending with the fat side down.

Preheat oven to 425 degrees.

Sprinkle the garlic powder and crushed rosemary over the top of the roast.

Put roast in the oven and cook uncovered for 30–40 minutes, or until a meat thermometer reads 135 degrees for medium-rare.

Remove from oven and allow to rest for 5 to 10 minutes.

Carve against the grain and serve, using the juices as a gravy.