Sous vide is the best way to prepare a rib roast, bone-in or boneless. You're guaranteed a perfect medium-rare roast from edge to edge with no babysitting or guesswork!
Liberally season the rib roast with kosher salt and black pepper. You'll want a thin, even layer of salt all over the roast and a sprinkling of pepper evenly coating it.
Place a small wire rack over a plate or rimmed baking sheet and place the roast on the rack. Refrigerate, uncovered, for 1-24 hours. The longer you can leave it, the deeper the salt will penetrate into the roast.
Add the vacuum sealed roast to the preheated water bath and make sure it's fully submerged. It's heavy enough that you shouldn't need to worry about it floating. Cook for 8-12 hours.
While the roast is in the ice bath, prepare the herb compound butter. In a medium bowl, combine all ingredients for the butter and mix until completely combined.
Remove the roast from the ice bath and from the bag and discard. Place the roast on top of the baking sheet, fat cap side up, and rub the butter all over the roast. Be generous!