Take the prime rib out of the fridge, put it on the rack from the roaster fat side up and allow it to sit until it’s at room temperature so it cooks evenly, approximately 2 hours.
If you want the seasoning to soak into the prime rib even more, season your prime rib 24 hours beforehand (you can also add some criss crosses to the prime rib with a knife to the let the seasonings soak in as well). Before you start to season, you’ll want to blot the prime rib with a paper towel to get rid of extra moisture so the seasonings will stick even better to the roast.
Rub butter over the roast and then liberally salt the roast on all sides (the salt also helps you achieve a crispy seared crust). Next mix together the black pepper, rosemary and thyme and spread evenly over the entire roast and then add your minced garlic (and can add the minced garlic or garlic cloves into the criss cross slits you made).
Preheat your electric roaster oven to 450°F (8-10 minutes). Then place the rack with the meat into the roaster.
Close the lid and continue to cook on high (450°F) for 15 minutes in order to sear the meat. Then bring down the temperature to 350°F. Let the prime rib rest for at least 15-30 minutes after you take it out from the roaster, depending on what size it is.
