How to Make It
Braise the brisket: About an hour before cooking, take brisket out of the fridge. Score long, shallow slashes about 1 in. apart on the fat side with a sharp knife (just down to the meat), then score in the opposite direction to crosshatch. Sprinkle meat on both sides with salt. Mix spices together, then sprinkle and rub all over brisket. Preheat oven to 250°.
Put brisket in a roasting pan just big enough to hold it and pour in enough coffee to come halfway up the sides. Cover tightly with foil.
Roast brisket about 8 hours, depending on weight (about 1 hour per lb.). If you're in a hurry, cook at 375° for 3 1/2 to 4 hours. When it's done, you should be able to put a fork all the way through it and pull the meat apart easily. If you can't, it's not done. "The smell really drives the dog mad overnight," says Best. Remove from oven and let cool until you can touch it.
Make barbecue sauce: Whisk all ingredients in a large bowl. Adjust seasonings to taste.
Put meat on a cutting board and pull into long shreds with two forks. Cut into bite-size shreds (about 2 in.) and put in a large bowl, along with juices from roasting pan. Add about half of barbecue sauce, enough to coat meat well. Shred meat more finely with your fingers, adding more sauce if you like.
Make slaw: In a large bowl, mix cabbage, carrots, cilantro, sesame seeds, and 1 1/2 tsp salt. Whisk together vinegar, honey, and oil. Taste and add more salt or vinegar if you like, then toss with slaw.
To serve: Preheat oven to 325°. Separate rolls into halves and toast on a baking sheet, cut sides up, until just crisp, 5 to 8 minutes. Spread with mayonnaise, then make sandwiches with beef and slaw (about 1/4 cup beef and 2 tbsp. slaw per slider). Serve with extra hot sauce.
Make ahead: Meat, through step 5, up to 2 days, chilled -(reheat at 350° until hot, about 30 minutes, before proceeding). Slaw and vinaigrette, up to 1 day, chilled separately (toss closer to serving). Composed sandwiches, 2 hours (or longer if you have space to chill them); reheat at 400° just until warm, about 3 minutes.