3-4 lbs. sirloin tip roast
1 clove garlic, split (opt.)
1 (18 oz.) bottle barbecue sauce

Rub meat surface with split garlic, if desired. To marinate, place roast in a plastic bag; set in a deep bowl. Pour barbecue sauce over meat; close bag. Marinate in the refrigerator 1 to 24 hours, turning occasionally.

Place roast, fat-side up, in a shallow pan, reserving barbecue sauce. Insert a meat thermometer in the center of meat until bulb rests in the thickest part of meat. Roast, covered in 325 degree oven. Remove roast from oven after 30 minutes (per pound for medium rare), add reserved sauce to the bottom of pan, cover and return to oven. Remove roast from oven when thermometer registers 135; allow to stand, covered with foil about 15 minutes before carving.