In a large mixing bowl, combine the diced chicken breast, mayonnaise or Greek yogurt, and Dijon mustard. Mix well until all the chicken is coated with the dressing.

Add the finely chopped celery and halved red grapes to the bowl. Stir to combine, ensuring the ingredients are evenly distributed throughout the salad.

Lay the whole wheat wraps flat on a clean cutting board. Place a few lettuce leaves in the center of each wrap.

Spoon a generous portion of the chicken salad onto the lettuce. Spread it out evenly, leaving a small border around the edges of the wrap.

Starting from one edge, carefully roll the wrap up tightly. The lettuce will help keep the chicken salad in place as you roll.

Slice the wraps in half diagonally for easier handling and a more attractive presentation.

Pack the chicken salad wraps in a lunchbox. They can be enjoyed as is or paired with a side of fruit or vegetables for a complete meal.