Remove and discard the skin from the breast portion of the rotisserie chicken. Pull white breast meat from the chicken to a cutting board and use your hands to shred it. You should have approximately 2-1/2 cups shredded chicken. Reserve dark meat for another purpose.
Preheat the oven to 350 degrees. Place 1/3 cup walnuts in a small baking dish and bake for 5 to 7 minutes or until lightly toasted. Remove from oven and set aside until cool enough to handle. Chop walnuts and set aside.
In a large mixing bowl combine Greek yogurt, mayonnaise, Dijon mustard, chopped dried cranberries, celery, red onion, lemon juice and zest, salt and pepper. Mix well to combine. Add shredded chicken and chopped walnuts and mix until well combined.
Divide mixture between the sandwich bread or wraps. Top with some of the broccoli slaw. Serve immediately or place in an airtight container in a chilled thermal bag to send to school with your child for lunch.