Crumble the blue cheese into a bowl and, using a fork, whisk in the olive oil. Set aside and let rest for 40-50 minutes. During the time, the cheese "melts" into the oil and makes a cloudy concoction.
Stir in the mayonnaise and vinegar. Add a dash of kosher or sea salt and a few grinds of fresh black pepper.
When ready to serve, stir thoroughly to combine and do not use sparingly.
Refrigerate any leftover dressing and use as a dip for celery sticks or as a salad dressing. It will keep up to 1 week or so.