Pat the roast dry, then season generously with kosher salt on all sides.
Set it on a rack over a sheet pan to dry brine and refrigerate uncovered for 24 to 48 hours.
Pull the roast out 2 to 3 hours before roasting.
Tie with a butcher's twine to maintain shape and help the roast cook evenly
To the roasting pan add your aromatic; rosemary, thyme, halved garlic, bay leaves, and lemon peel.
Drizzle with a little olive oil so they actually cook and not dry out.
Mix a simple paste of whole grain mustard, chopped rosemary, chopped garlic, and olive oil.
Rub the paste over the fat cap only, keep the sides mostly salt and pepper for clean beefy flavor.
If your fat cap is very thick, score it lightly in a crosshatch so the rub clings and renders better (do not cut into the meat).
Heat the oven to 250°F (120°C) to preheat.
Place the roast bone side down in the roasting pan (or on a rack if boneless).
Insert a probe thermometer into the center of the thickest part, avoid touching bone or fat pockets.
Roast at 250°F for a 12 lb roast this takes approximately 3 hours until the center reaches an internal temperature of about 118°F (47°C)
Pull from the oven and let it rest for atleast 30 minutes or upto 1hr and 30minutes
While the roast is resting, crank the temperature up to 500°F (260°C).
Return the roast to the oven for a short finish, about 10 to 15 minutes, just until the exterior looks deeply browned.
Once browned, you’re down, the roast is now ready
Slice, serve and enjoy
