In a mixing bowl, combine lime juice, sour cream, mayonnaise, garlic salt, chopped chipotle pepper, and fresh cilantro. Whisk until creamy and smooth. Refrigerate for at least 30 minutes.

In a small bowl, mix paprika, garlic powder, onion powder, cayenne pepper, thyme, basil, oregano, salt, and black pepper. Set aside.

Melt butter and dip each piece of fish into it, then coat with blackening seasoning.

Heat a skillet over medium-high heat, add oil, and cook fish for about 2 minutes on each side until flaky.

Warm tortillas, assemble tacos with cabbage, fish, Cotija, and drizzle the chipotle-lime sauce. Serve immediately.