01 - Place potatoes in a large pot. Fill with cold water to cover, add 1 tablespoon salt, and bring to a boil. Reduce heat and simmer for 10–12 minutes or until fork-tender. Drain and allow to cool slightly.
02 - While potatoes are cooking, fry chopped beef bacon in a large skillet over medium heat until crispy. Transfer bacon to a paper towel-lined plate to drain excess fat.
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 potatoes until fully coated.
05 - Add celery, green onions, shredded cheddar cheese, chopped parsley, and most of the cooked beef bacon (reserve some for garnishing). Gently mix until all ingredients are evenly distributed.
06 - Taste and season with additional salt and black pepper as needed.
07 - Transfer mixture to a serving platter or bowl. Garnish with reserved green onions, beef bacon, and extra parsley.
08 - Serve warm, at room temperature, or chilled depending on preference.