Pat the white fish fillets dry with paper towels and set aside for about 10 minutes to come to room temperature.

Combine chili powder, cumin, smoked paprika, garlic powder, onion powder, cayenne, salt, and pepper in a small bowl to create a spice rub.

Rub the spice mixture on both sides of the fish fillets evenly.

Heat olive oil in a skillet over medium-high heat until shimmering.

Add the seasoned fish fillets and cook for 3-4 minutes on each side until golden brown and flaky.

In a bowl, whisk together sour cream, mayonnaise, lime juice, lime zest, minced garlic, and cilantro until smooth.

Combine shredded cabbage, shredded carrots, sliced red onion, and chopped cilantro in a bowl.

Whisk together lime juice, olive oil, sugar, salt, and pepper, then dress the slaw mixture.

Warm the tortillas in a skillet for 30 seconds on each side.

Assemble tacos with slaw, fish, and lime crema, adding optional toppings as desired.

Serve immediately with lime wedges on the side.