In a medium bowl, combine the diced mango, red onion, chopped cilantro, and the juice of half a lime to create the salsa; season with a pinch of salt and set aside to let flavors meld.

In a small bowl, whisk together the sour cream and 1 tablespoon of fresh lime juice until smooth to create a simple lime crema; add a teaspoon of water if needed to reach drizzling consistency.

Pat the fish fillets dry with paper towels to ensure a good sear, then coat them generously on both sides with the Cajun seasoning blend.

Heat 1 tablespoon of olive oil in a large skillet, preferably cast iron, over medium-high heat until the oil shimmers and is very hot.

Add the fish fillets to the hot skillet and cook for 3 to 4 minutes per side until the spice crust is blackened and the fish flakes easily with a fork.

While the fish rests for a moment, warm the tortillas in a dry skillet over medium heat for about 30 seconds per side until they are soft and pliable.

To assemble, flake the fish into large chunks and divide among the tortillas, then top with shredded cabbage, a spoonful of mango salsa, and a drizzle of lime crema.