Step 1: Prepare the Brisket: Preheat oven to 300°F (150°C). Mix paprika, garlic powder, onion powder, cumin, chili powder, salt, and pepper. Rub the spice mixture evenly over the brisket. Heat olive oil in a large oven-safe pan or Dutch oven over medium-high heat. Sear brisket on both sides until browned (3-4 minutes per side). Add beef broth and BBQ sauce to the pan. Cover tightly with a lid or foil. Place in preheated oven and cook for 6-8 hours until brisket is tender and easily shredded.
Step 2: Make the Chipotle Slaw: In a large bowl, combine shredded green cabbage, red cabbage, carrot, and green onions. In a separate small bowl, whisk together mayonnaise, lime juice, chipotle in adobo sauce, honey, salt, and pepper. Pour dressing over cabbage mixture and toss until evenly coated. Refrigerate until ready to serve.
Step 3: Assemble Tacos: Warm tortillas in a skillet or microwave. Shred the brisket using two forks. Place a generous portion of shredded brisket on each tortilla. Top with chipotle slaw, fresh cilantro, and a squeeze of lime juice.