01 - Pat tilapia fillets dry with paper towels. Combine chili powder, cumin, smoked paprika, garlic powder, salt, and black pepper in a small bowl. Rub spice mixture evenly over both sides of fish. Drizzle with olive oil and lime juice.
02 - Heat a large nonstick skillet over medium-high heat. Place seasoned fillets in pan and cook for 3 to 4 minutes per side until golden brown and cooked through. Remove from heat and let rest for 2 minutes. Flake fish into bite-sized pieces.
03 - Combine shredded cabbage, carrots, and chopped cilantro in a large bowl. Add lime juice and olive oil. Season with salt and pepper to taste. Toss thoroughly until vegetables are evenly coated.
04 - Whisk together sour cream or Greek yogurt, lime juice, hot sauce if using, and salt in a small bowl until smooth and creamy.
05 - Heat tortillas in a dry skillet over medium heat for 30 seconds per side until pliable and warm, or microwave stacked tortillas for 20 to 30 seconds.
06 - Layer slaw and flaked tilapia onto warm tortillas. Drizzle generously with crema. Top with sliced avocado, fresh cilantro leaves, and serve with lime wedges on the side.
07 - Serve tacos immediately while fish is warm and tortillas are soft.