Anchovies add rich, subtle flavor to this classic dressing.
Roughly chop garlic and anchovy fillets; sprinkle with salt and drag the blade of a large knife at an angle across mixture until a paste forms. Transfer to a bowl and stir in lemon juice, mayonnaise, and mustard. Whisk in olive oil.
To store, refrigerate dressing in an airtight container, up to 3 days.