Heat oven to 350*.  Separate dough into 4 rectangles; firmly press perforations to seal.  Spoon 1/4 of onions, if desired, into center of each rectangle; top with 1/4 of Brie.  Top each with 1/4 of chicken, pressing into cheese.  Fold short ends over chicken, overlapping slightly.  Fold open ends over about 1/2 inch to form rectangle.  Press all edges to seal.  Place seam side down on ungreased 15x10x1 baking pan or cookie sheet.  Cut three 1-inch slashes on top of each roll to allow steam to escape.  Brush with egg; sprinkle with rosemary and parmesan.  Bake at 350* for 21-26 minutes or until golden brown. Garnish with tomato wedges if desired.  Makes four sandwiches.