Preheat oven to 350 degrees. Mix chicken, chopped broccoli and chopped onion. Add parsley, cheese, mustard to chicken mixture; mix well. Unroll crescent dough; separate into 16 triangles. Arrange triangles in a circle on a 13 round pizza pan with wide ends of triangles overlappin in the center and points toward the outside. (There should be a 5 inch diameter opening in center of pan.) Scoop chicken mixture evenly onto widest end of each triangle. Bring outside points of triangles up over filling and tuck under wide ends of dough at center of ring. (Filling will not be completely covered.) Bake 25-30 minutes or until deep golden brown.
Ham can be substituted for the chicken. I like to take this to office parties as it looks very festive. The filling can be made ahead of time and refrigerated until ready to assemble