Preheat oven to 350 degrees F.
Using your fingers, pluck the doughy section of bread away from the crust leaving a 1/4-inch thick collar of crust. Place the crusty collars in a large bowl and drizzle with olive oil. Toss and squish the bread like a sponge until the oil is evenly absorbed.
Place the oil-soaked crusty collars on a baking sheet, standing up so that the hot air can circulate through the "O", and bake for approximately 20 minutes, or until collars are crispy and golden brown.
Place the egg, in its shell, in boiling water for 40 seconds. Remove, run under cold water for 15 seconds to stop the cooking process, then use as directed.
To make caesar salad dressing, add salt and pepper to the salad bowl (this creates a sandpaper-like base that will make the next steps easier). Using the back of a soup spoon, grind the garlic against the wall of the bowl until it becomes a paste. Then add the anchovies, and once again use the back of the spoon to grind it into a paste. Follow the same procedure, adding the Dijon, egg yolk, lemon juice and Worcestershire sauce, 1 at a time. Make sure that each ingredient is blended into a smooth paste with the previous ingredients before proceeding.
Add the oil and vinegar. Blend well.
To serve, stand lettuce leaves upright in crouton collars. Drizzle 2 tablespoons of dressing overtop each serving, then sprinkle liberally with Parmigiano-Reggiano.
Note: If you don't have a rough wooden salad bowl, the dressing can be made (with some sacrifice) in a blender. Add the salt, pepper, garlic, anchovies, Dijon, lemon juice, Worcestershire and vinegar. Puree. Then add the oil and pulse a few times. Add the yolk and pulse a couple more times—just enough to blend it without causing the dressing to turn mayonnaisey.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.