In a medium-sized bowl, whisk together the garlic, anchovy paste, lemon juice, Dijon mustard, and Worcestershire sauce. Add the mayonnaise, ½ cup Parmigiano-Reggiano, salt and pepper, and whisk until well combined. This tastes better when made the day before and will keep in the fridge for several days.
Separate and wash the lettuce leaves, discarding the bottom ¼ core of each.
Dry the leaves, blotting them with paper towels. Make sure they are very dry, or you will end up with a watery dressing. Tear the leaves into bite-sized pieces.
NOTE: You can prepare your lettuce ahead of time as well. Just wrap the clean, separated, dried leaves in damp paper towels, then place them in a zipper-topped bag in the fridge. Tear them into pieces just prior to serving.