Preheat the oven to 375 degrees.
Drizzle the olive oil over the fish fillets, and apply salt and pepper to taste.
In a small bowl, combine the paprika, chili powder and cumin. Mix to combine.
Sprinkle the herb mixture over the fish, and rub it in with your hands on both sides. Bake the fish fillets for 20 minutes.
While the fish is baking, prepare the filling for your tacos. Shred the purple, cabbage, chop the tomatoes and avocado, and crumble or shred the cheese.
To assemble your fish tacos, cut the fish fillets into bite sized pieces. On a leaf of lettuce, add shredded cabbage, pinch of chopped tomato, pinch of chopped avocado, spoonful of fish, and a dollop of sour cream.