In a small bowl, combine mayonnaise, minced chipotle peppers in adobo, and 1 tbsp fresh lime juice. Whisk vigorously until the sauce is completely smooth and develops a creamy, orange-pink color. Set aside in the refrigerator.

In another mixing bowl, combine diced red tomatoes, diced white onion, chopped cilantro, the remaining 1 tbsp lime juice, and a generous pinch of salt. Toss gently to combine and let sit at room temperature.

Pat the cod fillets dry. Mix smoked paprika, garlic powder, cumin, and salt. Rub the cod with olive oil, then coat with the spice mixture. Sear in a hot cast-iron skillet over medium-high heat for 3-4 minutes per side until a deep golden-brown, blackened crust forms.

Heat a dry skillet over medium-high heat. Place the soft corn tortillas in the pan one at a time, cooking for 30 seconds per side until slightly charred. Wrap in a warm towel to keep pliable.

Nestle pieces of blackened cod into the center of a charred corn tortilla. Generously drizzle with the creamy chipotle mayo, and top with fresh pico de gallo. Serve immediately.