01 - Pat tilapia fillets dry with paper towels. Combine chili powder, cumin, smoked paprika, garlic powder, salt, and black pepper in a small bowl. Season both sides of fillets evenly with spice mixture, then drizzle with olive oil and lime juice.
02 - Heat large nonstick skillet over medium-high heat. Place seasoned fillets in pan and cook 3-4 minutes per side until golden brown and fish flakes easily with fork. Remove from heat and let rest 2 minutes, then flake into bite-sized pieces.
03 - Combine shredded cabbage, carrots, and chopped cilantro in large bowl. Add lime juice and olive oil, then season with salt and pepper. Toss thoroughly until vegetables are evenly coated.
04 - Whisk together sour cream (or Greek yogurt), lime juice, hot sauce if using, and salt in small bowl until smooth and well combined.
05 - Heat tortillas in dry skillet over medium heat for 30 seconds per side until pliable and slightly charred, or microwave between damp paper towels for 20-30 seconds.
06 - Layer warm tortillas with slaw and flaked tilapia. Drizzle crema generously over top. Garnish with sliced avocado, fresh cilantro leaves, and squeeze of fresh lime juice.
07 - Serve tacos immediately while tortillas are warm and fish is hot. Offer extra lime wedges and hot sauce on the side.