01 - Pat fish fillets thoroughly dry. Rub both sides with olive oil, Cajun seasoning, salt, and black pepper.
02 - Heat a large skillet or grill pan over medium-high heat until hot.
03 - Place fish fillets onto the heated surface and cook for 2 to 3 minutes per side until blackened and cooked through. Remove from heat and allow to rest for 2 minutes, then break into bite-sized portions.
04 - In a large mixing bowl, mash avocado with mayonnaise and lime juice until creamy. Add shredded cabbage, carrot, red onion, cilantro, salt, and black pepper, stirring until evenly combined.
05 - Heat tortillas in a dry skillet for 20 to 30 seconds per side or microwave briefly until pliable.
06 - Layer avocado slaw onto each tortilla. Top with blackened fish chunks and finish with desired garnishes, such as cilantro leaves, lime wedges, jalapeños, or hot sauce.
07 - Serve tacos immediately with additional lime wedges on the side.