Mixed Green Caesar Salad

INGREDIENTS

• 1/2 cup walnut halves (about 2 ounces)
• 1 large shallot, minced
• 1 large garlic clove, minced
• 2 anchovy fillets, mashed, plus 1/2 teaspoon anchovy oil
• 2 tablespoons fresh lemon juice
• 2 teaspoons Dijon mustard
• 1/2 teaspoon salt
• 1/4 teaspoon freshly ground pepper
• 1/4 cup olive oil
• 4 cups bite-size pieces of romaine lettuce (about 1/2 head)
• 4 cups bite-size pieces of arugula (about 2 bunches)
• 1/4 cup freshly grated Parmesan cheese