Here's Green Goddess Dressing, From cookbook:
Place in a blender:
1 cup mayonnaise
1/2 cup parsley sprigs
2 green onions, cut up
2 tablespoons tarragon vinegar (cider vinegar okay)
2 teaspoons sugar
1/4 teaspoons salt
1/4 teaspoon dry mustard
1/8 teaspoon garlic powder
1/8 teaspoon pepper
Cover and blend til smooth. Remove to bowl; blend in 1/2 cup plain yogurt. Cover; chill Makes 1 1/2 cups.
From Best Recipes cookbook, should be what you need. sg