In a bowl, combine the shallot, vinegar, mustard and honey. Whisk in the EVOO and season with salt and pepper. Add the chicken, celery, carrot, lettuce and tarragon; toss.
Trim the ends off the loaf of bread, then slice the loaf into six 2-inch-thick slices. Using a serrated knife and starting at the top, cut a pocket into each bread slice. Fill the bread pockets with the chicken salad.