I do a 7-rib prime every Christmas. Make sure your butcher separates the ribs and ties them back on, makes slicing much easier. I usually cut the strings, flip the ribs over, and re-tie, making it a "standing" rib roast. I don't trust times with meat that expensive, it's done when it's done. I start at 500 degrees for 20 minutes and drop to 325 and cook until the thermometer reaches 130 degrees.
I usually buy mine at least three days before cooking it. I place it in the roasting pan, sprinkle it liberally with Kosher salt, and cover with a flour sack towel in the fridge. I pull mine out to rest on the kitchen counter at least three hours before cooking. Good luck! Prime rib doesn't need any fancy rubs or anything, just liberal Kosher salt to season it and drow out some of the moisture. When you pull it out to rest, it should be dark red and look and feel dry or tacky. It's ready to cook!
edited to add: I use an inserted probe type thermometer with remote read. Once the cooking starts, do NOT open that oven door again until that thermometer reads 130, let rest and it will rise to 135 in about 15 minutes, you're ready to serve!
Edited by Slow Drifter (11/20/16 09:19 AM)
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