Preparation Pulse mayonnaise, buttermilk, vinegar, parsley, white and pale green parts of scallion, anchovy paste, and 1/4 teaspoon each of salt and pepper in a food processor until parsley and scallion are finely chopped. Transfer to a bowl and stir in scallion greens and tarragon. Chill until ready to use. CooksÂ’ note:Sauce can be chilled up to 1 day.
Preparation Pulse mayonnaise, buttermilk, vinegar, parsley, white and pale green parts of scallion, anchovy paste, and 1/4 teaspoon each of salt and pepper in a food processor until parsley and scallion are finely chopped. Transfer to a bowl and stir in scallion greens and tarragon. Chill until ready to use. CooksÂ’ note:Sauce can be chilled up to 1 day.