How to Cook Prime Rib on the Big Green Egg Using Reverse Sear

First of all, I'd like to explain something that is very confusing regarding the term "prime rib".  The word "prime" is NOT referring to the category of meat determined by the USDA.  Prime Rib is just a common term for the cut of meat from the cow (ie. brisket, flank, etc).  The USDA grades meats in three main categories, select, choice or prime.

So you can have three different kinds of Prime Rib:

Select Prime Rib
Choice Prime Rib
Prime Prime Rib

Most grocery stores don't even carry actual Prime-Prime Rib and most of it ends up at restaurants.  It is usually Select or Choice and should say so on the label so just make sure your getting what you think your getting.  Prime rib is also called "Standing Rib Roast".

Here's how I cooked it:

1. The day before, season the roast.  Slather in olive oil, salt, pepper, rosemary and thyme. Loosely cover in the fridge over night, preferably not air tight.
2. Let sit out on the counter for an hour or two to begin to warm up slowly.
3. Setup for an indirect cook, place setter legs up, drip pan, grate on.  
4. Put the meat on a v-rack in a roasting pan and put on the grate.
5. Cook at around 250 degrees to an internal temperature of 115.
6. Depending on your timing situation, you can pull and wrap and put meat in a cooler, or just let it rest on the counter (at least 30 min)
7. While resting, fire the egg up to 500-550 degrees and roast for another 10-15 minutes to create a great outer crust. I live to kind of roll it around on the grate to sear all sides.
8. Carve immediately.  The ends will be more done so the folks that like theirs more done should get those pieces.  The center should be full blown medium rare.