Combine first 11 ingredients in a medium bowl; toss well. Set aside.
. Cut baguette in half horizontally. Hollow out top and bottom halves of loaf, leaving a 1/2-inch border. Reserve torn bread for another use.
. Arrange lettuce and tomato on bottom half of loaf. Spoon chicken mixture evenly over lettuce and tomato. Replace top half of loaf; cut crosswise into 4 equal portions.