For dressing, in a small bowl whisk together oil, vinegar, mustard, pepper, and salt.
In a medium bowl combine chicken, avocado, tomatoes, and bacon. Pour dressing over chicken mixture; toss to coat.
Cut a wedge in the top of the bread about 1 inch from edges. Use your hands to pull out some of the inside of the loaf, leaving about a 3/4-inch shell. Layer in lettuce, chicken mixture, cheese, and eggs. Let stand 15 minutes before slicing carefully with a long serrated knife. Or, wrap and chill up to 2 hours.