Toss cabbage, 2 tbsp cilantro, 1 tbsp oil, 1 tbsp lime juice, 1/8 tsp salt, and pinch of pepper in a bowl; set aside for serving
In a separate bowl, combine mayonnaise, chipotle, garlic, remaning 1 tbsp cilantro, and remaining 1 1/2 tsps lime juice. Season with salt and pepper to taste. Set aside for serving
Pat fish dry with paper towels and brush with remaining 1 tbsp oil. Combine chili powder, 1/4 tsp salt, and 1/8 tsp pepper, then rub evenly over fillets
Cook fish in a cast iron skillet on high heat, until fish flakes apart when gentlym prodded, about 5 minutes per side. Transfer fillets to a cutting board when done
Warm up tortillas
Assemble the tacos! Cut the fish into small pieces and combine with the cabbage mix and spicy mayo mix