Combine the mayonnaise, mustard, and vinegar in a large mixing bowl. Set aside.
To Prepare the Salmon
(If you would like to make your own Cajun spice mixture, prepare now.)
Preheat air fryer to 400°(F).
Place the salmon on a large plate, flesh-side up, and pat dry.
Brush the flesh side of the salmon fillets with canola oil, sprinkle with the Cajun spice mixture and press the seasoning onto the salmon fillets using your hand or the back of a spoon.
Place seasoned salmon in air fryer basket or middle tray position, set to air fry at 400°(F) for 8-10 minutes (depending on thickness of salmon). Salmon will be done when internal temperature is 145°(F)
Continue cooking over medium-high heat, until the skin becomes crispy, and the fish is fully cooked through, about 5 to 6 additional minutes depending upon the thickness of the fillets.
To Prepare the Salad
In a large salad bowl, mix the Spring Mix Salad greens, carrot, onion, and scallions. Add the dressing and mix very well. Plate mixed greens adding salmon to each plate and serve immediately.