01 - Place potatoes in a large pot, cover with cold water, add 1 tablespoon salt, and bring to a boil. Reduce heat and simmer for 10–12 minutes until fork-tender. Drain and let cool slightly.
02 - In a large skillet over medium heat, fry chopped beef bacon until crisp. Transfer the bacon to a plate lined with paper towels to drain excess fat.
03 - Mix sour cream, mayonnaise, Dijon mustard, and black pepper in a large mixing bowl until smooth.
04 - Gently fold the warm, drained potatoes into the dressing until evenly coated.
05 - Stir in celery, green onions, shredded cheddar, parsley, and most of the cooked beef bacon. Combine gently for even distribution.
06 - Adjust with additional salt and black pepper as needed.
07 - Transfer to a serving dish. Top with reserved green onions, beef bacon, and parsley. Serve warm, at room temperature, or chilled.