Caesar salad, enjoyed since the 1920's, gets a flavour boost with the addition of Dijon mustard.
Place lettuce in large salad bowl.
Just prior to serving, put mayonnaise, oil, lemon juice, mustard, salt and pepper in a 2 cup measure. Whisk until smooth.
Add dressing and parmesan cheese to lettuce in bowl and toss. Sprinkle croutons on top.