Preheat your grill or skillet over medium heat. While heating, prepare the chicken by brushing it with olive oil and seasoning with salt and pepper.
Grill the chicken for about 7-10 minutes on each side, or until fully cooked (internal temperature should reach 165°F/75°C). Once cooked, remove from heat and let it rest for a few minutes before slicing.
In a mixing bowl, combine the honey, Dijon mustard, mayonnaise, and apple cider vinegar. Whisk together until smooth to create the honey mustard dressing.
In a large bowl, add the mixed salad greens, cherry tomatoes, cucumber, red onion, shredded carrots, and walnuts (if using).
Add the sliced chicken to the salad and drizzle with the honey mustard dressing. Toss gently to combine all ingredients.
Serve immediately on salad plates, garnished with additional walnuts if desired.
For added flavor, marinate the chicken in some of the honey mustard dressing for 30 minutes before cooking.
You can customize the salad by adding other vegetables or throwing in some cheese, like feta or goat cheese.
Leftover salad can be stored in the refrigerator, but it's best to keep the dressing separate until ready to serve to avoid sogginess.