Score the fat cap and season the pork belly the night before the cook. Using a sharp knife, cut a crosshatch pattern into the fat cap about a quarter inch deep - do not cut into the meat. This opens up the fat so it renders beautifully and allows the rub to penetrate. Pat the entire slab completely dry with paper towels. In a small bowl combine brown sugar, smoked paprika, kosher salt, black pepper, garlic powder, onion powder, cayenne, and dry mustard and mix thoroughly until uniform.

Apply the mustard binder and dry rub all over the pork belly. Coat the entire surface - all four sides and both ends - with a thin even layer of yellow mustard. This acts as a glue for your rub and will not make the final product taste like mustard. Immediately after the mustard coat, apply your dry rub generously on all sides, pressing it in firmly so it adheres. Wrap tightly in plastic wrap or place in a zip-close bag and refrigerate overnight, or for a minimum of 4 hours. This dry brine step is not optional - it draws moisture in, seasons deep, and sets you up for a killer bark.

Fire up the grill or smoker and set up for two-zone indirect heat. If using a kettle grill, bank your lit charcoal to one side and leave the other side empty. If using an offset smoker, build your fire in the firebox as normal. Add your cherry or apple wood chunks directly on the coals or in the firebox. Target an ambient cooking temperature of 250 to 275 degrees Fahrenheit at grate level. This is your low and slow zone where the magic happens. Allow the grill or smoker to come up to temperature and stabilize for 15 minutes before adding the meat.

Place the pork belly fat cap side up on the indirect heat zone of the grill or on the smoker grate. Do not place it over direct fire at this stage. Close the lid immediately and let the smoke and heat go to work. You are looking for thin blue smoke, not billowing white smoke - white smoke will make the meat bitter. Maintain your 250 to 275 degree Fahrenheit cooking temperature by adjusting vents on a charcoal grill or managing your firebox on an offset. Resist the urge to open the lid for the first 90 minutes.

Spritz the pork belly starting at the 90-minute mark. Open the grill and spray a light coating of your apple juice and water mixture over the entire surface of the pork belly. You are not drenching it - just a light mist to keep the exterior from drying out and to encourage bark development. Close the lid and repeat this spritz every 45 minutes throughout the cook. You will notice the color deepening from pink to amber to a rich mahogany as the rub caramelizes and the bark builds.

Monitor the internal temp throughout the cook and target 200 to 205 degrees Fahrenheit. Insert your instant read thermometer into the thickest part of the meat, avoiding the fat layer. At 250 to 275 degrees Fahrenheit your 3-pound slab will likely take 3.5 to 4.5 hours to reach this target, but always cook to temp not to time. When the probe slides in and out of the meat with almost no resistance - what pitmasters call butter-probe-tender - you are ready for the sear phase.

Sear the fat cap over direct high heat to finish the crispy skin. Once your pork belly has hit 200 to 205 degrees Fahrenheit internally, crank up or stoke your fire to create a blazing hot direct heat zone. If on a kettle grill, add a chimney of fresh hot coals to the pile. Place the pork belly fat cap side down directly over the flames. Watch it closely - you want a deep caramelized sear on that fat cap, which should take 3 to 5 minutes. The fat will crackle, blister, and turn a deep golden brown. Do not walk away during this step. Flip and sear the meat side for 2 additional minutes to add char and color.

Rest the meat before slicing - this step is non-negotiable. Remove the pork belly from the grill and place it on a clean wire rack or cutting board. Tent loosely with aluminum foil and allow it to rest for a minimum of 20 minutes, or up to 30 minutes for a thicker slab. Resting allows the juices that have been driven to the center of the meat by heat to redistribute back throughout every bite. Cut it too early and those precious juices run all over your cutting board instead of staying in the meat where they belong.

Slice and serve your grilled pork belly. Using your sharpest slicing knife, cut the pork belly crosswise into slices about three-quarters of an inch thick. You will see the smoke ring - that pink layer just beneath the bark - which is the visual proof of your low and slow craft. Each slice should have a shatteringly crispy fat cap on top, a deep smoky bark on the exterior, and a tender, juicy interior. Serve immediately with your favorite BBQ sauce, pickled vegetables, or simply on its own. The meat speaks for itself.