Here it is
We haven't tried this recipe.
Interesting that John Mauldin butterflies the piece, scores meat, treats both sides with a rub, closes it up and then scores and treats outsides with rub. Also, surprised that he serves immediately out of the oven BUT I assume that it is because the piece has already sat and is just getting heated up. Colleen
"First, the most crucial ingredient is a great piece of meat. You simply cannot skimp on the quality. And this is going to surprise people, but I have found that the best-quality prime rib comes from Costco. You can get a delicious 12- to 13-pound, already boned prime for about $120—$130.
About four hours before you’re going to cook the prime, take it out of the refrigerator and bring it up to room temperature. And then make the hand rub. Finely chop up two onions and place in a fairly large bowl. Then grab some fresh rosemary. It’s best if you can actually pick it off a plant somewhere near you, but most good Whole Foods or other organic grocers have relatively fresh rosemary. Take off the leaves and discard the stems. Chop the rosemary finely. I probably use six to eight long stems of rosemary. Honestly, don’t worry about using too much rosemary — just make sure to chop it finely.
Add some form of coarse salt. At least one cup. More if you like your meat a little salty. Remember, this rub is going to go mostly on the outside. Then add 6—8 ounces of coarse-ground pepper. Lately, I have found smoked coarse-ground pepper at Whole Foods. It really does seem to add a little extra kick. Then throw in a generous amount of Cavender’s Greek Seasoning. I might use 1/3 of one of their larger containers. Now slowly add a decent-quality olive oil to the bowl and stir until you get a consistent paste. (Over the course of time, you will develop your own sense of how you want your ingredients combined, and how much of what.)
And now we have to prepare the prime itself for seasoning. Take a sharp knife and essentially butterfly the prime, leaving maybe a 1-½ inch connection at the back. Then score the meat on both the inside and the outside every inch and and a half or so with a ½-inch-deep cut. Then take the rub and apply it on first the inside of the prime, working the rub into those scores you have made, so that more of the flavor can seep into the meat. Then fold the prime back together, and repeat the process on both the top and bottom of the meat. Place the prime in a roasting pan that has a rack that stands at least about ½ inch off the base of the pan. Now, this is important. Get a good meat thermometer, preferably one that is electronic and that will alert you when the meat is at the proper temperature. Have your oven preheated to 200° — yes, we are going to slow-cook it. Cooking a prime too fast will end up making it not as tender.
When the prime is not bone-in, it will generally take about two to three hours to cook, depending on size. When the meat gets to 120°, take it out of the oven. That should mean it is about medium rare on the inside. If it will be more than 30 minutes before you eat, put it in an oven that is at about 100°, just to keep it warm (but not to cook it further). Fifteen minutes before you are ready to serve it, put the prime back into the oven, which has now been preheated to 500°. Leave it in there for 10 minutes to sear the outside. Take it out of the oven, put it on your large wooden chopping board, cut it into the sizes you want to serve, and take it immediately to the table."
John Mauldin's Prime Rib Recipe