Cook whole potatoes 20-30 minutes until tender. Drain and rinse in cold water until cool. Cube and refrigerate until ready to use. I like to keep the peels on, but cool potatoes peel easily if you want to remove the skins at this time. Whisk sour cream and milk together and season with salt and pepper (which means taste as you mix until your liking). Stir in celery, chives, red onion and bacon. Stir in cubed potatoes and taste again. Adjust salt and pepper to taste. If the salad is too thick, add another tablespoon of milk to form a rich saucy consistency. Spoon potato salad into serving container(s) and sprinkle with shredded cheese and minced parsley and refrigerate until ready to serve. This salad can be made the day before, just wait to top the salad with the shredded cheese and fresh parsley until ready to serve.
Even if the salad appears soupy, remember that the potatoes will absorb lots of the moisture.
If you are planning to take this dish on a picnic, pack into a couple of containers, keeping the extra containers cold until needed to avoid spoilage.