In a blender combine mayo, sour cream, milk, and seasonings. Blend until smooth.
Alternatively you can put ingredients in a bowl and whisk vigorously.
Pour mixture into a bowl, stir in blue cheese crumbles.
Cover and refrigerate for at least 20 minutes before serving. Best if refridgerated a couple hours or the night before.
Will keep in refrigerator in air tight container for up to one week.