How to Make It
Place chicken in a medium bowl. Process anchovy fillets, garlic, lemon juice, red wine vinegar, mustard, Worcestershire sauce, salt, and pepper in a blender until smooth. Gradually add olive oil, and process until smooth; stir in Parmesan cheese. Pour dressing over chicken, and toss to coat.
Stir together mayonnaise and garlic powder in a small bowl. Brush cut sides of bread evenly with mayonnaise mixture. Heat a large skillet over medium-high. Cook bread, cut side down, in hot skillet, until toasted and golden brown, about 2 minutes. Divide chicken mixture and lettuce leaves evenly among bottoms of toasted bread; cover with bread tops.