Insert potatoes into a large pot, covering with cold water and a pinch of salt. Bring to a boil before lowering heat to simmer until fork-tender, 20-25 minutes. Drain and cool before tossing with celery and onions.
Fry bacon until godel brown and drain. 1 Tbl of bacon grease can be reserved and substituted for equal measure of olive oil.
Whisk mayonnaise, sour cream, lemon juice, oil and/or backon fat and minced basil. Season with salt and pepper.
Toss vegetable mixture with dressing and stir in reserved bacon. Garnish with chiffonaded basil. Serve immediately or refrigerate.