Place olive oil, lemon juice, anchovy fillets (if using) and Worcestershire in blender. Whirl until smooth. Stir in garlic, Parmesan, salt and pepper. Reserve half of mixture for dressing. Combine remaining half with chicken in resealable plastic food-storage bag. Marinate in refrigerator for 1 hour.
Meanwhile, toss torn lettuce with reserved dressing in salad bowl. Cover and refrigerate.
Prepare grill. Remove chicken from marinade; discard any extra marinade.
Grill chicken about 4 minutes per side or until no longer pink in center. Cut each chicken breast crosswise against grain at 45-degree angle into 3 pieces.
Prepare garlic bread following package directions. Cut one quarter of loaf into bite-size cubes. Save remainder of garlic bread for other meals.
Arrange lettuce in 4 bowls. Top each with 3 pieces of chicken and bread cubes. Garnish each salad with Parmesan shavings and a twisted anchovy fillet.