1) Coat the salmon with the Cajun seasoning on both sides.
2) Into a frying pan, pour the oil and heat it over high heat till it is almost smoking.
3) Put the salmon, skin side up, in the pan and cook for about 7 minutes, till it has blackened.
4) Flip the salmon over and cook for another 1 minute.
5) Take the pan off the heat and set it aside.
6) To a tortilla, add some of the lettuce, cilantro and sour cream. Flake the salmon and place it in the prepared tortilla. Repeat with the other tortillas.