How to Make It
In a large pot of boiling water, cook the lobsters until bright red all over, about 8 minutes. Drain the lobsters and when cool enough to handle, crack the claws and knuckles and remove the meat. Split the tails lengthwise, remove the meat and remove and discard the dark vein. Cut the tail meat in half lengthwise. Refrigerate the lobster meat until ready to use.
In a small bowl, combine the minced garlic cloves, lemon juice, anchovies, egg yolk (if using), Worcestershire and mustard. Whisk in the olive oil, then add 2 tablespoons of the Parmesan cheese and season with salt and pepper.
Preheat the oven to 400°. In a small saucepan, combine the butter with the smashed garlic cloves. Cook over low heat until the garlic has flavored the butter, about 2 minutes. Let cool slightly, then discard the garlic. In a cake pan, toss the bread cubes with the garlic butter. Spread them in an even layer and bake until golden brown, about 5 minutes.
In a large salad bowl, combine the romaine, frisée and celery root. Pour the dressing over the lettuce mixture and toss well. Add the croutons and remaining 1/4 cup of Parmesan cheese and toss well again. Mound the salad on 4 plates. Garnish each salad with a lobster claw and half of a lobster tail.