Dice the cooked chicken into about ½" cubes and place in a large mixing bowl. Add grapes and walnuts and toss to combine and set aside.
In a separate small bowl, combine the mayonnaise, sour cream, diced celery, red onion, parsley, seasoned salt and pepper. Stir until well combined. Pour the dressing over the chicken and mix until everything is coated. Cover the bowl and refrigerate for at least 1 hour.
After the salad has chilled for at least 1 hour, give it a stir and season to taste with salt and pepper. Lay a few lettuce leaves along the center of each tortilla and line up 2-3 slices of tomato on each wrap. Season lightly with salt and pepper then add about ½–¾ cup of chicken salad on top and fold the tortilla burrito-style. Wrap tightly with parchment paper and serve. Enjoy!
One Last Thing
Since tortilla wraps come in so many different flavors, it will be fun to experiment with your favorite!