Poke the roast beef in several places with a fork. Prepare the marinade and pour it into a shallow dish or airtight plastic bag, reserving 2 tbsp (30 ml) to brush the roast beef during cooking. Marinate the roast beef in the refrigerator for 12 to 48 hours. Discard the used marinade. Insert the meat thermometer into the center of the roast beef, grill fat side up, or use the rotisserie above a pan to collect the fat, with the BBQ lid closed, over medium heat and indirect heat, without exceeding the cooking temperature, to 160°F or rare 140°F.