01 - Combine green cabbage, red cabbage, carrot, and cilantro in a large bowl. Add lime juice, olive oil, salt, and pepper. Toss thoroughly to coat all vegetables. Refrigerate until ready to assemble tacos.
02 - Whisk together mayonnaise, lime juice, hot sauce (if using), smoked paprika, salt, and pepper in a small bowl until smooth and well combined. Set aside at room temperature.
03 - Mix paprika, garlic powder, onion powder, oregano, thyme, cayenne, black pepper, and salt in a small bowl. Pat fish fillets completely dry with paper towels. Rub both sides with olive oil, then coat evenly with the spice mixture, pressing gently to adhere.
04 - Heat a large cast iron skillet over medium-high heat. Add a small amount of olive oil if needed. Sear fish fillets for 2-3 minutes per side until blackened and cooked through. Remove from heat and break into large bite-sized pieces.
05 - Place warm tortillas on a serving platter. Top each with pieces of blackened fish, a generous scoop of slaw, and a drizzle of mayo sauce. Serve immediately with lime wedges on the side.