Trim off excess fat from the brisket. Some fat will melt down while it bakes, but not the majority, so I like trimming it. There is a river of fat between the flat and the tip, trim most of the fat out, leaving it still connected.
Cover the entire brisket in mustard and then sprinkle the salt and pepper all over.
Place the brisket on a cookie sheet, cover with foil and place in the fridge until you are ready to smoke.
Turn your smoker on, let it smoke, then turn the temperature to 225.
Take the foil off of the brisket, leaving it in the pan, place on the smoker.
Smoke for 6 hours.
Turn the heat up on the smoker to 250 and smoke another hour.
After 7 hours, remove the brisket and wrap tightly in butcher paper. Place back on the smoker.
Turn the temperature back down to 225 and smoke another 5 hours.
Remove the brisket and wrap the whole thing in foil, including the butcher paper. Let rest for 2 hours.