When the meat is this good, you can get by seasoning it simply but liberally with coarse salt (kosher or sea) and coarse, freshly ground black pepper. But being of the “more is more” school of thought, I like to mix up a quick wet rub consisting of garlic, herbs, salt, pepper, lemon zest, and extra-virgin olive oil. Slather on the rub just prior to grilling.
Step 1: Make the herb paste. Place the garlic, herbs, salt, pepper, and lemon zest in a food processor and finely chop. Work enough oil to obtain a coarse paste, scraping down the sides of the bowl with a rubber spatula.
Step 2: Using the tip of a paring knife, make small holes in the roast on all sides about 1-1/2 inches apart. Using the tip of your index finger or the handle of a spoon, widen the holes. Place a tiny spoonful of herb paste in each hole, forcing it in with your finger. This will use up about half the herb paste. Spread the remaining herb paste over the roast on all sides. Note: you can cook the roast right away, but it will have even more flavor if you let it marinate in the refrigerator for 1 to 2 hours.
Step 3: Set up your grill for indirect grilling and preheat to medium-high (400 degrees). (Ideally, you’ll be cooking on charcoal.) Place a drip pan in the center.
Step 4: When ready to cook, place the rib roast, bones rising upwards, on the grill grate over the drip pan. If using wood chips, toss them on the coals. Indirect grill the prime rib crusty and brown on the outside and cooked to the desired degree of doneness inside, 1 to 1-1/2 hours for medium-rare. Use an instant-read meat thermometer inserted into the very center of the prime rib through the large end to test for doneness: cook to 120 to 125 degrees for rare; 130 to 135 degrees for medium-rare. We won’t go any more well done than that. Remember, the prime rib will continue cook as it rests.
Step 5: Transfer the prime rib to a cutting board (preferably one with a well—a grooved border—to catch the juices when you carve it). Lay a sheet of aluminum foil over the prime rib (do not bunch the foil around it or otherwise tightly wrap it, which would make it soggy). Let the prime rib rest for 15 to 20 minutes.
Step 6: To carve the prime rib, if you’ve tied the roast—and I hope you have—remove any strings. Using a sharp carving knife or an electric knife, carefully slice off the rib bones following the curvature of the meat. Slice the roast crosswise, then cut the ribs apart and serve them on the side. Alternatively, leave the ribs attached and carve the roast with them. (Note: Portion sizes will necessarily be much larger if this method is used.)