Combine avocado, cilantro and lime zest in a bowl. Set aside. Microwave tortillas according to package directions. Spread each tortilla with one quarter of the avocado mixture. Then layer one quarter of the turkey, one quarter of the cranberry sauce followed by 1 collard leaf. If desired, sprinkle with salt and pepper to taste. Fold the sides over and roll up to enclose filling. Cut rolls in half on a slight diagonal.