Remove the prime rib from packaging, and pat it dry. Trim excess fat, silver skin, and ragged edges, leaving a uniform fat cap (about ¼ inch / 0.6 centimeter).
1 large boneless prime rib
Tie the roast lightly with butcher’s twine to create an even cylinder.
In a small blender or food processor, combine salt, rosemary, thyme, and oil. Pulse until a coarse salt-herb paste forms.
¼ cup kosher salt, ¼ cup fresh rosemary leaves, ¼ cup fresh thyme leaves, 2 tablespoon neutral oil
Rub the mixture evenly over the roast. Place on a rack over a sheet pan and refrigerate uncovered for 24-48 hours.
Remove the roast from the refrigerator one to two hours before cooking. Pat the roast dry, and season it generously with freshly cracked black pepper.
2 tablespoon black pepper
Preheat the oven to 250°F (121°C).
Place roast on a rack in a roasting pan (or sheet pan).
Roast for three and a half to four hours, or until the internal temperature reaches 118-120°F (47-48°C) for medium-rare or to your desired doneness, about 30-35 minutes per pound.
Remove the roast from the oven, tent it loosely with foil, and rest for 20-60 minutes. Reserve the pan drippings and set aside. Use the drippings to create Yorkshire pudding. (See below)
Heat a cast-iron skillet or griddle over high heat until very hot. Add one tablespoon of oil (15 milliliter).
Sear the roast on all sides until deeply browned and crisp.
Loosely tent the prime rib again, and rest for 20-30 minutes before slicing.