Balsamic Caesar Salad

Ingredients

• One 2-ounce can flat anchovies, drained and coarsely chopped
• 3 tablespoons balsamic vinegar
• 2 tablespoons mayonnaise
• 1 tablespoon Worcestershire sauce
• 1 teaspoon minced garlic
• 1/2 teaspoon freshly ground pepper
• 1/4 cup plus 2 tablespoons extra-virgin olive oil
• 1/4 cup freshly grated Pecorino Romano cheese
• 2 heads romaine lettuce (about 1 pound each), torn into bite-size pieces
• 1 small red onion, thinly sliced
• 1 cup homemade or store-bought plain or Parmesan croutons