Trim the excess fat from the flat of the Packer Beef Brisket, leaving a thin fat cap (about 1/4 inch) to keep the meat moist while it smokes.
Lightly coat the entire brisket with a thin layer of Yellow Mustard to help the seasoning adhere; you won’t taste the mustard after smoking.
Season generously and evenly on all sides with Kosher Salt and freshly cracked Coarse Black Pepper, pressing the rub into the surface to form a good bark.
Preheat your smoker to a steady 225–250°F (107–121°C) and place the brisket fat-side up; smoke until a deep mahogany bark develops and the internal temperature reaches about 160°F (71°C), which can take several hours.
If the brisket hits the stall and needs help through it, wrap it tightly in butcher paper (or foil) and return to the smoker to continue cooking.
Continue smoking the wrapped brisket until the internal temperature reaches 195–203°F (90–95°C) and a probe slides into the meat with little resistance; this indicates tenderness.
Remove the brisket from the smoker and let it rest, still wrapped, in a cooler or insulated container for at least 1 hour to let the juices redistribute.
Unwrap and slice the brisket against the grain into thin slices, separating the flat and the point if you’ve trimmed both muscles for even slicing.
Serve the slices on soft White Bread topped with thin rings of White Onion, crunchy Dill Pickle Chips, a few Pickled Jalapeños for heat, and a drizzle of Texas-Style Barbecue Sauce.
