01 - Place potatoes in a large pot, cover with cold water, and add 1 tablespoon salt. Bring to a boil, then reduce heat and simmer for 10 to 12 minutes, or until potatoes are fork-tender. Drain thoroughly and let cool slightly.
02 - In a large skillet over medium heat, fry chopped beef bacon until crispy. Remove from the skillet and transfer to a plate lined with paper towels to drain.
03 - In a large mixing bowl, whisk together sour cream, mayonnaise, Dijon mustard, and black pepper until smooth.
04 - Add the warm, drained potatoes to the bowl with the dressing. Gently fold to coat the potatoes evenly.
05 - Incorporate celery, sliced green onions, shredded cheddar cheese, chopped parsley, and most of the cooked beef bacon into the potato mixture. Reserve a portion of green onions and bacon for garnish. Gently mix until combined.
06 - Adjust seasoning with additional salt and black pepper as desired.
07 - Transfer the salad to a serving dish. Garnish the top with reserved green onions, crispy beef bacon, and fresh parsley. Serve warm, chilled, or at room temperature according to preference.