Preheat the oven to 350°F. Spread the walnuts in a single layer on a baking sheet. Toast or 6-8 minutes until fragrant. Set aside to cool.
In a medium-size mixing bowl whisk together the mayonnaise, sour cream, honey, vinegar and lemon pepper until combined.
Add the walnut, chicken, celery, apples, grapes and raisins. Toss until coated.
Chill in an airtight container for up to 2 hours. Serve on lettuce leaves.