To make the croutons, heat oven to 350°F and arrange rack in middle. Combine smashed garlic clove and 3 tablespoons olive oil and infuse for 20 minutes.

Remove garlic from oil (it can be reserved to make the dressing). Toss oil and the 3 cups bread cubes together in a large bowl, season with salt and pepper and toss again. Spread bread out in a single layer on a baking sheet and bake, stirring occasionally, until golden and crunchy, 10 to 15 minutes.

To make the dressing, combine 2 tablespoons lemon juice, 1 teaspoon Dijon mustard, 1 teaspoon Worcestershire, 1/2 teaspoon salt, 1 minced garlic clove, 1 minced anchovy fillet, 1/4 teaspoon black pepper, and 1/4 cup freshly grated parmesan cheese in a large glass jar with a tight-fitting lid (a Mason jar works well). Cover tightly and shake until incorporated and uniform.

Add 1/4 cup olive oil and shake once more until incorporated. Taste and add more salt if necessary. Use immediately, or store in refrigerator for up to 3 days; shake again before using.

To assemble, wash, dry and tear lettuce into a large bowl. Add Parmesan, croutons, and half of the dressing (save other half for another salad). Season with salt and freshly ground black pepper and toss, making sure everything is coated. Taste and add more salt and pepper if necessary, serve immediately.