01 - Preheat oven to 400°F. Line a baking tray with parchment paper.
02 - In a bowl, toss cod fillets with olive oil, chili powder, smoked paprika, cumin, garlic powder, salt, pepper, and lime juice until evenly coated. Arrange the seasoned fish on the prepared baking tray.
03 - Bake for 12 to 15 minutes, or until the cod is opaque and flakes easily when tested with a fork.
04 - While the fish bakes, combine shredded cabbage, carrot, cilantro, lime juice, olive oil, and salt in a bowl. Toss thoroughly until well mixed.
05 - Stir together sour cream or Greek yogurt, lime juice, and lime zest. Season with salt and pepper to taste.
06 - Warm tortillas in a dry skillet over medium heat or in the microwave until pliable.
07 - Layer slaw onto each warm tortilla, top with flaked pieces of baked cod, and drizzle generously with lime crema. Add avocado slices if desired, garnish with fresh cilantro, and serve alongside lime wedges.