Preheat your oven to 350°F (180°C) and spread the walnuts on a baking sheet. Toast them in the oven for about 5 minutes, or until they are golden and aromatic. Keep a close eye on them as they can burn quickly. Once done, remove and let them cool before chopping into smaller pieces.

While the walnuts cool, cube your poached chicken breasts into bite-sized pieces and transfer them to a large mixing bowl. Next, core the red and green apples, then chop them into cubes. Slice the celery stalks thinly. Add the diced apples, sliced celery, and chopped parsley to the bowl with the cubed chicken.

In a separate small bowl, combine the low-fat mayonnaise, fresh lemon juice, and Dijon mustard. Whisk these ingredients together until smooth and well blended. The dressing should be creamy with a tangy twist from the mustard, perfectly complementing your Chicken Waldorf salad.

Pour the dressing over the chicken and vegetable mixture, ensuring everything is well coated. Gently fold the ingredients together, taking care not to mash the apples. Once fully mixed, add the chopped walnuts and stir again to incorporate. Taste and adjust the salt to enhance the flavors in your Chicken Waldorf salad.

Cover the bowl with plastic wrap and let your Chicken Waldorf salad sit at room temperature for about 10 minutes. This resting time allows the flavors to meld beautifully, creating a harmonious blend of tastes and textures that enhance each bite of the salad.

While the salad rests, separate the romaine or gem lettuce leaves. Rinse them gently under cold water, then pat them dry with a clean kitchen towel or use a salad spinner. This creates a crisp and fresh base that perfectly complements the creamy Chicken Waldorf salad when served.

Arrange the lettuce leaves on a serving platter to create a lovely base for your salad. Spoon the Chicken Waldorf salad mixture generously on top of the lettuce, allowing the vibrant colors to show. This dish is now ready to be served, bringing a refreshing and nutritious option to your lunch table!