I made this prime rib yesterday and have been hearing conflicting ways on how to make the perfect prime rib. The fact of the matter was a reliable source that tried all 3 roasts has informed me that mine was by far the best. So how do you make an excellent prime rib?
Prep: 3 hours
First of all the roast has to be good. This does not mean a true USDA "prime"rib but get a good piece of meat. Make sure you ask the butcher to separate the ribs from the roast. If you have already gotten the roast and the ribs are not separated this is okay, you can do it yourself. Simply start cutting at the beginning of the ribs and cut the roast away from the ribs. Easy. Next use kitchen string to tie the ribs back to the roast. These ribs will act as a rack holding the roast off of the pan when you go to cook it. It should look like the roast below when done with the ribs detached but tied back onto the roast.
Also: DO NOT TRIM THE FAT! The fat is what flavors this piece of meat. Your butcher should have trimmed most of the excess fat and left a healthy amount on the roast.
Next you want to be sure to leave the roast out of the fridge for 2/3 hours before you are ready to cook it. If at all possible you want the meat at room temperature before going into the oven.
When the roast is ready to go in I like to dice a bunch of garlic and rub the outside down with it. I also like to place some fresh rosemary sprigs on the roast and rub maybe a little salt and pepper as well. A trick I use that some may frown upon is to "inject" the roast with garlic. I do this by taking a clove of garlic and smashing it slightly so that it releases it's oils. I then take this clove and jam it deep into the roast. My mom used to own a garlic injector but she has long since lost it and does not know where to get one. If anyone knows where I can get one please let me know in the comments!
For the record, if all you do is rub some salt/pepper on the roast that is fine as well but the garlic really is what can make your good roast great.
Cooking:
Now onto the part that really seems to confuse people: cooking times.
First of all you should not attempt this roast without a meat thermometer.
Next, crank the oven up. Way up. You want it at 500 degrees. Place your roast (Ribs should be on the bottom of the roast creating a rack) in a baking pan and place it in the 500 degree oven for 15 minutes. At the 15 minute mark you want to turn the oven down to 325 degrees. This is when you start timing your prime rib. The times are as follows.
15-16 minutes per pound for a rare roast.
17-20 minutes per pound for a medium rare roast.
I do not recommend trying to cook your prime rib well done! This meat is best with some rare in it, you can always take your slice and pan fry it or even cook it in au jus to your overdone temp.
The best way to know when to take out your prime rib is obviously the temp. Using a meat thermometer you do not want to remove the roast until the thermometer ready 115 degrees in the thickest part of the roast. I would not let it get past 125 internal temp before pulling the roast.
The most important thing is to let the roast sit for 20 minutes after you have taken it out of the oven. This is very important as the roast will continue to cook once removed from the oven.
After your roasts 20 minute resting period is over you want to cut the kitchen string and remove the roast from the ribs placing it on a cutting board. Cut your individual steaks and enjoy!