Whisk the buttermilk, mayonnaise, sour cream, minced green onion tops, lemon juice, minced garlic, lemon zest, salt, pepper, and Creole seasoning, if using, together in a nonreactive mixing bowl. Use the dressing immediately, or store in a covered nonreactive container in the refrigerator for up to 3 days.
Combine all ingredients thoroughly.
Yield: 2/3 cup
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch, published by William Morrow, 1993.