How to Make It
Preheat the oven to 300°. In a bowl, combine the coriander, cumin and mustard seeds, paprika, chile powder, 1 tablespoon each of salt and pepper and the ginger. Set the brisket in a large enameled cast-iron casserole and rub the spices all over the meat.
Heat the olive oil in a large saucepan. Add the onions and garlic and cook over moderate heat, stirring often, until softened, about 5 minutes. Stir in the vinegar, brown sugar, Worcestershire and soy sauces; simmer for 5 minutes. Add the tomatoes and bring the sauce to a simmer.
Pour the sauce over the brisket. Cover with foil or a tight-fitting lid and bake for 4 hours, turning twice, until very tender and the sauce is thickened. Transfer the brisket to a platter. Pour the sauce into a medium saucepan and let stand for 10 minutes, then skim off the fat.
Light a grill. If using charcoal, scatter the hickory chips over the coals. If using a gas grill, place the chips in the smoker box or scatter them over the heat bars. Lightly oil the grate. Grill the brisket covered over a medium-low fire for 45 minutes, turning once, until nicely charred. Transfer to a cutting board.
Meanwhile, boil the sauce over moderately high heat until reduced to 4 cups, about 20 minutes. Transfer the sauce to a blender or food processor and puree until smooth, then pour into a bowl. Season with salt and pepper.
Thinly slice the brisket across the grain on the diagonal; arrange on the rolls. Top with the lettuce, tomatoes and red onions, drizzle with some of the barbecue sauce and serve.