When I was a little girl, this is the only dressing that my mother would buy. I had no idea that other dressings existed until I got older.
1/2 cup mayonnaise
1/4 cup parsley, chopped
1/4 cup sour cream
3 tablespoons tarragon vinegar (or white wine vinegar)
2 teaspoons lemon juice
4 teaspoons anchovy paste
1 clove garlic mashed
Place all of the above ingredients in a blender. Process until smooth. Refrigerate until ready to serve. Keeps 4 weeks in the refrigerator.