Pat the roast dry and place it on rack with a tray underneath. Cover loosely with paper towels and set in the coldest area in the refrigerator and allow it to dry for no less than 5, but no more than 7 days, changing the paper towel frequently.

Remove the roast from the refrigerator and allow to stand at room temperature for 1 hour. Preheat oven to 250°F.

Heat a large cast iron skillet over medium-high to high heat.

Season the roast well with kosher salt and fresh ground pepper, pressing it into the meat.

Put the roast in the skillet, fat side down first and brown well all over. Remove from the pan and put on cutting board and cut the roast away from the bone in one piece. Return the meat back to the bone and tie it back, on end to end, with kitchen twine.

Place the roast in a pan with a rack and roast until the internal temperature reaches 120°F for rare and 125°F for medium rare, about 20 minutes per pound (about 1 ½ to 2 hours).

Remove roast from the oven, tent loosely with foil and allow to rest for 30 minutes.

While the roast rests, prepare the sauce. Put the beef broth and thyme in a saucepan and bring to a boil. Simmer 10 minutes. Add Worcester sauce and pepper to taste. After the roast has rested, cut the twine and remove it from the bone. Add bones and accumulated juices to the sauce and simmer a five more minutes. Strain sauce.

Carve the roast into slices and serve immediately with ramekins of sauce on the side.