Place potatoes in a Dutch oven or large pot and cover with water. (Do not peel them.) Bring water to a boil, reduce heat to maintain a simmer and boil 20 minutes, or until just tender all the way through. Drain potatoes, let cool, and peel skin off. Slice potatoes into bite-sized pieces.
Dice bacon and place into a nonstick skillet. Cook over medium-heat until crisp. Using a slotted spoon, remove bacon to a paper towel-lined plate. Discard all but about 2 tablespoons bacon fat.
Add onion and celery to bacon fat and cook until soft.
While onion is cooking, combine vinegar, SPLENDA® Sweetener, chicken broth, salt, mustard, and pepper in a small bowl.
Once onion and celery are softened, sprinkle flour over them and cook 1 minute.
Stir in chicken broth mixture and cook for 1 minute.
Add potatoes to pan and stir to mix everything together. Check for seasoning and add more salt and pepper if needed.
Sprinkle with bacon and parsley just before serving. Best served warm or at room temperature.
Notes
I like to boil the potatoes with the skins on and then peel them after they are cooked. I think this helps prevent the potatoes from becoming waterlogged. If your potatoes are small, you can cook them whole. Add more cider vinegar or more SPLENDA® Sweetener to create the right balance of sweet and sour to suit your personal taste.