The Croutons:

Remove croutons from oven and toss with 2 tablespoons Parmesan. Allow them to cool.

The Dressing:

For the dressing. Combine egg yolk, lemon juice, 12 anchovies, garlic, and mustard in the bottom of a cup that just fits the head of an immersion blender, or in the bottom of the food processor. Process for no more than 7 seconds so that the egg is not so processed that it inhibits proper emulsification.

Then with blender or processor running, slowly drizzle in olive oil until a smooth emulsion forms. 

Note: you have made more dressing than you need. Save what you dont use. Alternatively you could make the dressing the time-honored way by combining at the bottom of a large salad bowl a raw egg yolk and approximately 1/3 of the listed quantities of lemon juice, mashed anchovies, garlic and mustard and then while vigorously whisking, slowly incorporate 1/3 a cup of olive oil.

Season to taste with salt and pepper.

The Lettuce:

Remove and reserve for another night the outer leaves until you get to the point where there's no flop to the greens at all.

Slice the leaves off their stems

Rip the larger leaves into several pieces and leave the smaller ones intact. This salad is meant to be cut into bite size pieces by each quest on their own plates.

Wash leaves and carefully dry. 

Serving:

Assemble large salad bowl, dressing, croutons, lettuce, dressing, minute-cooked egg and parmesan. If the idea of an undercooked egg is not appetizing to some guests, you can omit altogether or simply add in and toss the egg yolk.

Constantly tossing:

Start by adding a few tablespoons of dressing to the salad bowl (unless you assembled teh dressing in the time-honored way) followed by the lettuce. Toss carefully but thoroughly.

Add croutons

Once coated, toss in the egg yolk

Then add the cheese 

Sprinkle fleur de sel and pepper

Serve immediately and dress with anchovy slices

Have extra dressing and anchovies available on the side for those who prefer more