1. Prep the prime rib. Trim the excess fat, season with kosher salt (1 tsp per pound of meat) then refrigerate uncovered 24 to 72 hours before cooking.
2. Sous vide the rib roast: Vacuum seal and cook in a 133° F water bath for 6 to 12 hours.
3. Chill it: Fully chill the roast in a water bath (still in the bag) or refrigerate overnight before smoking.
4. Apply a dry rub. Remove from the bag, leave wet and apply a dry rub on all sides.
5. Smoke it On smoke boost setting if your pellet smoker has it, or at 225° F until the internal temp of the rib roast reaches 130° F.
6. Sear it with a blow torch, on a hot grill, skillet, or under the broiler for 1 to 2 minutes just to crisp up the fat cap. 7. Slice and enjoy!