Preheat oven to 375°F (190°C). Unroll crescent dough; separate into 16 triangles. With wide ends of triangles toward the center, arrange 8 triangles in a circle on a Pizza Stone. Corners of wide ends will touch and points will extend 1 inch beyond edge of baking stone. Arrange remaining 8 triangles in center, matching wide ends. Seal seams using Baker's Roller. (Points will overlap in center; do not seal.)Place mayonnaise, mustard and black pepper in a large mixing bowl. Chop turkey using Salad Chopper. Add turkey, celery, parsley and cranberries to mixing bowl. Grate cheese using Adjustable Coarse Grater, add to turkey mixture and mix together. Using Medium Scoop, scoop filling over seams of dough, forming a circle. Sprinkle chopped walnuts over filling.Beginning in center, lift one dough triangle across filling mixture. Continue alternating with outer triangles, slightly overlapping to form wreath. Tuck last end under first.Lightly beat egg white; brush over dough using Chef's Silicone Basting Brush. Bake 25-30 minutes or until golden brown.