Heat oven to 375°F. In medium bowl, mix filling ingredients until well blended.
If using crescent rolls: Unroll dough; separate into 4 rectangles. Place on ungreased cookie sheet; press each into 6x4-inch rectangle, firmly pressing perforations to seal. If using dough sheet: Unroll dough; cut into 4 rectangles. Place on ungreased cookie sheet; press each into 6x4-inch rectangle.
Spoon about 1/2 cup chicken mixture onto center of each dough rectangle. With knife, cut each corner of each rectangle from edge to within 1/2 inch of filling. Bring the 8 points of each rectangle up over filling; firmly pinch to seal, forming a square.
Bake 16 to 21 minutes or until deep golden brown. Remove from cookie sheet. Garnish each with 1 tablespoon Caesar dressing and 1/4 cup shredded lettuce.