Trim and remove the fat cap from the point. Trim the fat cap over the flat to 1/4”. Trim any excessive/hard fat from the surface.
Combine the injection ingredients and mix well. Load into a pistol grip injector. Inject the flat meat in a grid pattern, pumping in as much liquid as will stay inside before moving to the next injection site.
Wipe excess injection liquid from the surface of the brisket. Season with Plowboys BBQ Bovine Bold and Cattleman’s Grill Trail Dust All Purpose Seasoning. When the seasonings appear wet on the surface the brisket is ready to go on the grill.
Build a bed of hot charcoal in the firebox of the Big Green Egg. Place the Kamado Joe SloRoller in the grill and stabilize the temperature at 275ºF-300Fº. Place 1`-2 fist sized chunks of hickory smoking wood on the hot coals, then return the top of the SloRoller to its place. Install the cooking grates, then transfer the brisket to the grill.
Smoke the brisket until a dark bark is formed and the internal temperature passes 160ºF, about 4-5 hours. No need to add more smoking wood during this period of time, as the original chunks will add plenty of smoke flavor.
Wrap the brisket in foil and continue cooking until the brisket is tender and offers little resistance when probed with an instant read thermometer, about 1-2 hours more. The internal temperature in the flat will be around 205ºF.
Remove from the grill and place in a cooler to rest. Rest for at least one hour before slicing to serve.