Pat the pork completely dry with paper towels. Set it fat side up on a tray or a large sheet of plastic wrap.

Score the fat cap in a crosshatch pattern, 1/4 to 1/2 inch deep, without cutting deep into the meat.

Rub a thin layer of mustard over the whole roast. For more smoke flavor, stir a small dab of liquid smoke into the mustard first.

Cover all sides generously with the rub, working it into the score marks and crevices.

Wrap tightly in several layers of plastic wrap. Refrigerate overnight on a tray.

Heat the oven or smoker to 250°F. Unwrap the pork, saving the juices. Set it fat side up on a rack over a large, deep pan and pour the saved juices over the top. (In a smoker, put it straight on the grates.)

Insert an oven-safe probe into the thickest part, away from the bone. Bake uncovered until it reaches 200 to 205°F, usually 10 to 12 hours, but it varies. Running behind? Once it hits about 185°F, bump the heat to 275 to 300°F.

Wrap in a few layers of foil and rest 1 to 2 hours. It stays hot for hours wrapped, or longer in a dry cooler packed with towels.

Pull out the bone, then shred, removing any soft fat and gristle. Break up the crusty bark and mix it back in.

Serve on buns with BBQ sauce, pickles, coleslaw and red onion, or over mac and cheese.