Preheat the oven to 400°F (200°C). Cover the chicken breast with vegetable oil, paprika, all-purpose seasoning, dried thyme, dried rosemary, cayenne pepper, salt, and black pepper.
Bake the seasoned chicken breast for 30-40 minutes or until fully cooked. Allow to rest for a few minutes.
Once the chicken finishes baking and is still hot, use two forks to shred the chicken breast into bite-size pieces.
Grab a large mixing bowl and add the shredded chicken pieces. Then incorporate the chopped celery, diced red onion, mayonnaise, lemon juice, salt, and ground black pepper.
Transfer the chicken salad to an airtight container. Refrigerate for at least 2 hours (or up to overnight).
When ready to serve, heat a skillet over medium heat. Swirl a little butter in the hot skillet.
Place toasted challah bread slices on a clean work surface. Scoop the chilled chicken salad onto one slice and use a spoon or spatula to spread it evenly over the toast.
Arrange assembled chicken salad sandwiches on a serving platter. Serve immediately with crispy dill pickle chips and your favorite potato chips on the side if desired.
