Add the mayonnaise, sour cream, gorgonzola cheese crumbles, and salt and pepper and whisk well to combine.

Taste now to see if you think it needs more salt and pepper. You can stop now (without the buttermilk) if you want more of a mayonnaise-like consistency to spread on sandwiches.

Add buttermilk a little bit at a time and whisk until you reach the right consistency. I usually only need about 3 tablespoons to hit a thick dressing stage but if you're making this for salads, you might want to add more.

Store in a jar or container with a lid in the refrigerator for no more than 2 weeks.