Pat the salmon fillets dry with paper towels and sprinkle both sides generously with Cajun seasoning, pressing it lightly into the flesh.
Heat a tablespoon of oil in a skillet over medium-high heat until shimmering and just starting to smoke.
Place the seasoned salmon fillets skin-side down (or flesh-side down if skinless) in the skillet, and cook for about 4-5 minutes until the edges start to turn opaque and develop a dark, spiced crust.
Using tongs or a spatula, carefully flip the fillets and cook for another 3-4 minutes until the salmon is cooked through and flakes easily with a fork.
While the salmon cooks, warm the corn tortillas in a dry skillet or microwave until soft and pliable.
Remove the salmon from the skillet and let it rest for a minute before flaking it into large chunks with a fork.
Spread a layer of sour cream over each tortilla, then top with chopped lettuce and a few pieces of the flaky, smoky salmon.
Squeeze fresh lime juice over the assembled tacos for a bright, tangy finish and serve immediately.
