If making the cilantro-lime sauce, add the ingredients to a blender, blend until smooth, and refrigerate. If you bought some or just plan on using sour cream, that's good too!
Preheat the air fryer for 5 minutes.
Place the fish on paper towels to absorb any excess moisture. Pat the fillets dry. Season both sides generously with the taco seasoning.
Cook:
Spray the pre-heated basket with oil, then place the seasoned fish pieces in a single layer in the air fryer.
Air-fry at 400F for 8 to 10 minutes. After 5 minutes of cooking, open the air fryer and flip the fish pieces over to cook on the other side. If using cod, which is thicker, you might need an extra 2 minutes of cooking time. The fish is ready when it flakes easily, and it's white inside. Remove the cooked fish to a plate and coarsely chop it. Squeeze half a lime over the fish and save the other half for serving.
Assemble:
Warm up your tortillas and top them with a layer of slaw, cooked fish, and a drizzle of cilantro lime sauce (if using) or your favorite toppings.