1 cup mayonnaise
1 garlic clove
1 Tablespoon fresh chives, chopped
4 scallions, thinly sliced
1/3 cup fresh parsley leaves, loosely packed
1/3 cup sour cream
2 Tablespoons tarragon vinegar
Salt and pepper to taste
Anchovy or anchovy paste, to suit your taste (optional)
Put all ingredients in a blender container and blend on high until smooth.
Pour into a suitable container, cover and store in the refrigerator.
Shake before using.