How to Make It
Heat the oven to 325°. Toss the bread cubes with 1 tablespoon of the oil and spread on a large baking sheet. Bake until crisp on the outside and lightly browned, about 15 minutes. Let cool.
Meanwhile, put the lemon juice, garlic, Parmesan, anchovy paste, mustard, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper in a blender and blend until smooth. With the blender running, slowly add the 3/4 cup oil. Alternatively, whisk together everything but the oil and then add the oil slowly, still whisking.
Heat the broiler. In a broiler pan or on a baking sheet, toss the shrimp with the remaining 1 tablespoon oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Broil the shrimp, turning once, until just done, about 4 minutes in all.
In a large bowl, combine the lettuce, tomatoes, croutons, and shrimp. Add the dressing and toss to coat.