Preheat oven to 350ºF. Spread pecans on a baking sheet and toast, shaking sheet once or twice, until nuts are fragrant, about 5 minutes. Transfer to a plate to cool.
Whisk together orange juice, vinegar, mustard, honey, shallot, olive oil and salt in a large bowl until well combined. Remove 1/4 cup vinaigrette. Add chicken and apples to bowl with remaining vinaigrette and toss.
Arrange greens on four dinner plates. Drizzle with reserved 1/4 cup vinaigrette. Top with chicken mixture. Sprinkle with nuts and serve.
Love this salad.