In a small bowl, whisk together the paprika, ancho chile powder, smoked paprika, cayenne pepper, cumin, coriander, garlic powder, onion powder, oregano, and sea salt to make the blackening seasoning.

Pat the cod fillets dry with paper towels, then coat them generously with the seasoning blend. Reserve 1 teaspoon of the seasoning for the sauce. Let the fish marinate for at least 30 minutes or up to 3 hours in the refrigerator.

In a separate bowl, whisk together the mayonnaise, sour cream, lime juice, and the reserved teaspoon of blackening seasoning until smooth and creamy. Cover and refrigerate until ready to serve.

Heat a large nonstick skillet over medium heat. Melt 1 tablespoon of butter until foamy.

Add the seasoned fish in a single layer without overcrowding the pan. Cook for 3–4 minutes per side until beautifully blackened and the fish flakes easily with a fork. Add additional butter as needed while cooking the remaining fillets.

Transfer the cooked fish to a plate and gently break it into large bite-sized pieces.

Warm the corn tortillas in a dry skillet or directly over a gas flame for a few seconds per side.

Assemble the Blackened Fish Tacos by filling each tortilla with flaky cod, shredded cabbage, pico de gallo, and a generous drizzle of the creamy lime sauce.

Serve immediately with fresh lime wedges for squeezing over the tacos.