bj68, if you want the roast rare - med-rare (as that recipe indicates) try the following Heston Blumenthal method instead.
First, get one of these
Then use it to sear your roast on all sides, taking no more than about 7 or 8 minutes total to do so. (You want browning, not cooking)
Set your oven to 125°F - 130°F. (If you do this when you start the searing process, the oven should be up to temp by the time you're finished). Use a store-bought oven thermometer to check temps, don't rely on the temperature-o-meter built in to your oven. They're about as useless as the French during a German invasion.
Put the roast on a sheet tray or cookie sheet and put the lot into the oven. Let it cook for 24 hours. (The roast will be done in about 5-6 hours, but the extra time will impart a quasi dry aged effect on the flavor of the meat.) You can add the herbs de provence as per the Ron Lock recipe when you put everything int the oven.
Out of the oven, rest for 10 minutes or so. Carve according to your desires. You can cut it into individual ribeye steaks (you'll want to sear the cut sides in a screaming hot pan), or slice into the most delectable prime rib you've ever had.
Imo, 500°F is way
too hot to be cooking animal proteins if you really want to retain any of their natural texture. Temps that high should be reserved for searing.