Build a medium-hot fire in a charcoal grill, or heat a gas grill to high. Combine all dried spices in a small bowl. Sprinkle over fish, reserving about 1 tablespoon. Brush grill grate with oil. Grill fish until cooked through, about 5 minutes per side. Using a fork, coarsely shred fish.
Meanwhile, combine sour cream and reserved seasoning. Set aside.
Fill tortillas with fish. Drizzle with crema. Squeeze fresh lime wedges over tacos and sprinkle with grated cheese.
by The Savvy Kitchen