Whisk together all ingredients except Parmesan, making sure the anchovy paste gets fully incorporated. Stir in the Parmesan and set aside.
Wash and chop the romaine, then transfer to a large mixing bowl. Pour the dressing over the lettuce and toss with tongs until all of the salad is coated with dressing.
Transfer salad to serving bowls (4 small ones or 2 larger ones), then sprinkle generously with prepared croutons and Parmesan, then add a crack of black pepper if desired. Serve immediately.
To make ahead: Chop and store the lettuce in a covered bowl in the fridge. Make the dressing and store in a mason jar or other sealed container in the fridge. Bake the croutons and allow to cool completely before storing in an airtight container on the counter.
Feel free to adjust the anchovy paste to your taste.
Extra dressing can be stored in the fridge for about a week.
The only way to get a truly real food version of Worcestershire is to make your own (I like this homemade Worcestershire recipeI like this homemade Worcestershire recipe). But if a 1/2 tsp of regular store bought Worcestershire doesn't bother you, buy Annie's organic Worcestershire or whatever brand you like.
This recipe is great as-is, but topping it with protein like chicken or salmon makes an even more satisfying one dish meal!