Gather all your ingredients on the countertop to ensure you have everything ready to go.
In a medium mixing bowl, add 1 cup of mayonnaise and 1 cup of sour cream. Use a whisk or spoon to combine them until smooth.
To the creamy mixture, add 1 teaspoon of Worcestershire sauce and 2 to 3 teaspoons of fresh lemon juice. Mix well to incorporate these flavor boosters.
Gently fold in 2 to 3 ounces of crumbled blue cheese, being careful not to overmix to maintain texture.
Add buttermilk a tablespoon at a time until you reach your desired consistency.
If using, stir in 1 tablespoon of snipped chives and finish with a sprinkle of freshly-ground black pepper to taste.
Taste the dressing and adjust flavors with more lemon juice or Worcestershire sauce as needed.
For the best flavor, let your dressing chill in the refrigerator for at least 30 minutes before serving.
