Mix all the ingredients for the spice rub together and dredge the fish fillets in it. leave to marinate for at least 1 hour.
Heat a little oil in a an over medium-high heat. Cook the fish for about 2 minutes on each side. Press lightly in the hot pan to flake the fish into pieces.
In the meantime, mix all the ingredients for the creamy sauce together.
Serve the fish stuffed into the tortillas with the creamy sauce and any other fillings of your choice.