01 - Place potatoes in a large pot, cover with cold water, add 1 tablespoon salt, and bring to a boil. Lower heat and simmer for 10 to 12 minutes until fork-tender, then drain and let cool slightly.
02 - While potatoes cook, fry chopped beef bacon in a large skillet over medium heat until crisp. Transfer to a plate lined with paper towels to drain excess fat.
03 - In a large mixing bowl, whisk together sour cream, mayonnaise, Dijon mustard, and black pepper until smooth.
04 - Add drained, slightly warm potatoes to the bowl with the dressing. Fold gently until the potatoes are evenly coated.
05 - Stir in celery, green onions, shredded cheddar cheese, parsley, and most of the cooked beef bacon, reserving some for garnish. Mix until thoroughly combined.
06 - Taste and adjust seasoning with additional salt and black pepper, if needed.
07 - Transfer salad to a serving platter or large bowl. Garnish with reserved green onions, bacon, and parsley. Serve warm, at room temperature, or chilled.