Make sure not to bring the internal temperature of the beef above 135, max.
This recipe, from one of my cookbooks, works well for me. It produces great results.
"Standing Rib Roast
This undisputed king of beef roasts is often mistakenly called a Prime Rib Roast. But you really can't call it that unless you have purchased a USDA Prime Standing Rib roast. If you buy USDA Choice, then you just call it a standing rib roast, same cut, different quality. There are a number of ways to cook this hunk of meat. But all of them use slow, low heat to preserve and enhance the delicate flavor.
You can get very involved with this roast. A classic way to prepare a standing rib roast is to completely pack the meat in very coarse salt. This forms a crust which seals the meat. I haven't tried this technique, but it sounds like it would work well.
We are going to keep things simple, allowing you to experience a no hassle approach with delicious results. You will need an oven-safe meat thermometer for this one. Though a barbecue works, we will use the oven.
Ingredients:
1 standing rib roast, any size and with chine bones intact
Salt
Pepper
Preheat the oven to 450'- F. Place the roast on a suitable work surface(cutting board). Rub the entire roast with cooking oil. Sprinkle salt and pepper liberally over the meat surface.
Place on a rack inside a shallow roasting pan, bone-side down.
Place the thermometer into the thickest portion of the
roast, taking care to avoid touching the bone. Place the roast
into the oven and cook for fifteen minutes. Reduce the oven
temperature to 250 degrees F. and allow to cook until the meat
thermometer reads 127 degrees. Remove from the oven and let
rest for 20 minutes. Remove the bones from the meat and
carve 1/4" thick slices against the meat grain. Serve with
horseradish and meat sauce condiments, and your favorite
veggies (sweet potatoes go well with rib roasts)."
Copied from "You Can Be a Great Cook with Beef" and distributed with permission of the author (me).
Seeeeeya; Goodweed of the North