The Cajun seasoning is prepared. In a small bowl, the sweet paprika, smoked paprika, garlic powder, onion powder, oregano, thyme, cayenne, salt, and pepper are combined and whisked until fully incorporated.
The chicken is prepared. If using fresh chicken breasts, they are seasoned with a small amount of the Cajun blend. The olive oil is heated in a skillet over medium heat. The chicken is cooked for 5-7 minutes per side until golden brown and cooked through, reaching an internal temperature of 165°F -8. The chicken is then set aside to rest for 5 minutes before being chopped or shredded. For convenience, a rotisserie chicken is often used instead.
The dressing is made. In a large mixing bowl, the mayonnaise, sour cream, and lemon juice are combined. Two tablespoons of the prepared Cajun seasoning are added to the bowl. The ingredients are whisked together until smooth.
The mix-ins are added. The finely diced celery, red onion, and apple (if using) are added to the bowl with the dressing.
The chicken is incorporated. The cooked, shredded chicken is added to the bowl.
Everything is combined. All ingredients are folded together with a spatula until the chicken and vegetables are evenly coated with the spicy dressing.
The salad is chilled. The bowl is covered with plastic wrap and placed in the refrigerator for at least 30 minutes. This resting period is crucial, as it allows the flavors to meld and the salad to become thoroughly chilled -3-5.
The final seasoning is adjusted. Before serving, the salad is taken out of the fridge and stirred. A taste test is conducted, and additional salt, pepper, or a pinch of cayenne is added if desired.