Cook the chicken by poaching, grilling, or roasting until it reaches an internal temperature of 165°F, about 15–20 minutes. Allow it to cool slightly, then shred or dice.

While the chicken cools, wash and dry the mixed greens thoroughly. Slice the apples thinly and prepare the red onion if using. Toast the nuts in a dry skillet for about 5 minutes until fragrant.

In a large mixing bowl, whisk together the maple syrup, Dijon mustard, apple cider vinegar, and olive oil until smooth. Season with salt and pepper.

In a large serving bowl, combine the mixed greens, diced chicken, apple slices, toasted nuts, dried cranberries, and red onion. Drizzle half the dressing and toss gently.

Serve immediately, drizzling additional dressing on top if desired.