Wrap tortillas in aluminum foil and place in oven set at 300 degrees. Alternatively, just before serving, warm the tortillas in a microwave, wrapped in a damp paper towel.
Puree avocado, garlic, juice from one lime, cilantro, yogurt and ½ teaspoon salt in a mini prep or food processor until smooth and creamy.
Cut cod into cubes (about ¾-inch to 1 inch) and spread out on a plate. Sprinkle with Cajun seasoning and salt. Toss to coat with the spices.
Heat butter in a large non-stick skillet over high heat. When butter is melted and just starting to brown, add in the cod. Let cook, stirring once or twice until cooked through, about 6 minutes. Remove from the heat.
Divide the cod among the tortillas, top with cabbage and avocado cream. Cut the remaining lime into wedges. Serve the tacos with lime and pico de gallo.
