1. Core lettuce, and soak in cold water 15 minutes. Drain; separate leaves, and set aside.
2. Place chicken in food processor, and pulse until coarsely chopped or minced. Heat oil in a large nonstick skillet over medium-high heat. Add chicken, and sauté, stirring often, 5 minutes or until chicken is cooked through. Stir in shallots and next 3 ingredients. Stir in Pepper-Lime Dressing.
3. To serve, spoon chicken mixture into center of lettuce leaves, and garnish, if desired.