It's not difficult to roast a perfect prime rib, so long as you have a good heavy cast iron skillet and digital meat thermometer handy.
First, preheat the oven to 200 degrees. Season the outside of the meat with steak seasoning. Pat the seasoning into the sides of the meat.
Sear the meat on top of the stove in the cast iron skillet (you can use a heavy skillet, but the cast iron is the best choice as it gives it the best crust). You will have to sear each side separately, about three-to-five minutes per side at high heat. Keep turning until all the sides are seared. Sear does not mean burn, just brown it and turn, as cast iron can heat up to a very high heat. Beware that you cannot be distracted while you are doing this step - you must pay attention and keep turning it and searing.
Insert the digital meat thermometer probe into the thickest part of the roast (don't hit the bone with the probe) and place the meat on a broiler pan, bone side down, and roast at 200 degrees until the temperature reaches 130 for bright pink (medium rare). If you like the meat a bit closer to medium, go to 135 but I wouldn't go beyond that as it will start to get well done. It will take about 45 minutes per pound, up to a maximum of four to five hours. Be sure to go by the temperature, not the time.
Next is the most important step in roasting: Let it rest about 20 minutes before slicing. This assures you will have a very juicy roast. Use a large knife to slice off the bones, then cut into the meat to slice pieces as thick as desired and serve with ground horseradish.
Leftovers make a superb prime rib hash when combined with fried potatoes. Enjoy!