COOK IT.
To prep your prime rib, allow it to sit out at room temperature for 4 hours. This will help the beef cook more evenly. Once marinated and seasoned to your liking, transfer the roast to a roasting pan, bone side down.
Split your firebox into two heat zones: turning half of your burners to high and keeping the other half off. By the time its ready, you want the temperature inside your grill to read 500ºF.
Place your roast fat side up onto the grill over indirect heat, and start a timer for 2 hours 15 minutes. (Calculate your initial cooking time by allowing 5 minutes per pound of meat. For this example, we’re using a 9 lb. roast, which makes our initial cooking time 45 minutes.)
When the timer reaches 1 hour 30 minute, turn your grill burners off without opening the lid. The roast will continue cooking on the grill for another 1 hour and 15 minutes (for a total cooking time of 2 hours). While your prime rib continues to cook, we’ll prep your side dishes.
Scrub and wash your sweet potatoes. If you aren’t using organic potatoes, go ahead and peel those suckers, too. Then, slice your spuds into ½ in. thick rounds, place them on skewers, and brush with olive oil and your favorite seasoning.
To prep the Brussels sprouts, first remove any yellowing outer leaves. Then, place them into a large, microwave-safe mixing bowl and heat in the microwave on high for 3 minutes. When these are done, season as desired and place them on skewers, too.
When the timer reaches 15 minutes, remove your roast from the grill and let it rest while you grill your sides. Adjust the heat zones so that half of your burners are on medium and half are on high.
Place your sweet potato skewers over direct, medium heat, and cook for 7 minutes per side.
When the timer reaches 10 minutes, toss your Brussels Sprout skewers over direct, high heat. They’ll need just 5 minutes per side.