Place potatoes in a pot of boiling salted water for 10 minutes or until tender and easily pierced with a fork. (I recommend adding 1-2 tablespoons of vinegar to boiling water to prevent potatoes from overcooking)
Remove potatoes from pot once tender and rinse under cold water to cool.
Add mayo, sour cream, Dijon, and vinegar to a large bowl and mix to combine.
Then add crumbled bacon, blue cheese, and green onions and combine further. Finally, add the cooked potatoes to the bowl and toss to coat. Add salt and black pepper to taste.
Can serve immediately, but flavors will meld better if left in the fridge overnight.
Notes
Leftover potato salad should be stored in an airtight container in your refrigerator and not left at room temperature when serving for more than two hours. Enjoy the leftovers within one week.