Prep the brisket by shaping it and removing the silver skin and hard fat. Inject the brisket with beef tallow to enhance tenderness and juiciness. This will help keep the meat moist during the smoking process.
Season the brisket by applying a thin layer of mustard as a binder. Generously coat the brisket with the all-purpose rub seasoning. Allow the seasoned brisket to sit for one hour to allow the flavors to penetrate the meat.
Fire up the pellet smoker and set the temperature to 215 degrees Fahrenheit. Place a water pan in the smoker to maintain moisture. Smoke the brisket overnight for approximately 8 hours or until the internal temperature reaches 165 degrees Fahrenheit.
Once the brisket reaches 165 degrees Fahrenheit, wrap it tightly in butcher's paper along with a small amount of beef tallow. Place the wrapped brisket back in the smoker and increase the temperature to 250 degrees Fahrenheit. Continue smoking until the internal temperature reaches 203-205 degrees Fahrenheit, or until the brisket is probe tender.
Remove the brisket from the smoker and let it rest for 2-3 hours in a cooler, still wrapped. This resting period allows the juices to redistribute, resulting in a moist and tender brisket
While the brisket is resting, prepare the Chipotle Honey BBQ Sauce. In a saucepan over medium heat, combine ketchup, apple cider vinegar, honey, brown sugar, Worcestershire sauce, chipotle sauce, garlic powder, onion powder, pepper, and kosher salt. Whisk the ingredients together and let the sauce simmer over medium heat for 6-8 minutes. Remove from heat and let it cool before using.
Slice the Kings Hawaiian buns horizontally, keeping them connected. Place them on a baking sheet.
Layer pepper jack cheese on the bottom half of each bun. Pile up chopped brisket on top of the cheese.
Slather a generous amount of the Chipotle Honey BBQ Sauce over the brisket. Add more slices of pepper jack cheese on top.
Place the top half of the buns over the cheese and brush them with melted butter. Sprinkle a pinch of salt over the buttered buns.
Preheat your smoker to 350 degrees Fahrenheit. Place the assembled sliders on the smoker and smoke for approximately 20 minutes, or until the cheese is melted and the buns are toasted.