Step 1

Add sour cream, water, avocado, cilantro, lime juice, lime zest, and serrano pepper into a blender.

Step 2

Process until smooth, scraping down the sides as needed. Add more water as needed to achieve desired consistency. Transfer to a small bowl and refrigerate.

Step 3

Combine paprika, brown sugar, garlic powder, onion powder, salt, cumin, chili pepper and black pepper in a small bowl.

Step 4

Sprinkle seasoning evenly over both sides of the fish filets.

Step 5

Heat oil in a large cast-iron skillet or sauté pan over medium-high heat.

Step 6

Add fish to pan then cook 2 to 3 minutes on each side or until the desired degree of doneness. The surface will blacken in color quickly so keep a close eye on the fish.

Step 7

Warm tortillas according to package directions.

Step 8

Divide fish evenly among tortillas.

Step 9

Serve with lime wedges, tomatoes, cabbage, and cilantro.