Ingredients

1 cup mayonnaise 

1 cup fresh flat-leaf parsley leaves 

1 scallion, roughly chopped 

1 tablespoon fresh tarragon leaves 

1 teaspoon white-wine vinegar 

2 anchovy fillets, or 1 1/2 teaspoons anchovy paste (optional) 

1 garlic clove, coarsely chopped 

Preparation

In a food processor, combine all of the ingredients. Process until smooth and creamy.