• Step 1: Place the cubed potatoes in a large pot and cover with water. Bring to a boil over high heat, then reduce heat to medium-low and simmer for 10-12 minutes, or until the potatoes are tender when pierced with a fork. Drain the potatoes and set aside to cool slightly.
• Step 2: In a large skillet, cook the bacon over medium heat until crispy, about 8-10 minutes. Transfer the bacon to a paper towel-lined plate and crumble once cooled. Reserve the bacon grease in the skillet.
• Step 3: Add the diced onion to the bacon grease and sauté over medium heat for 5-7 minutes, or until the onions are soft and translucent.
• Step 4: In a small bowl, whisk together the apple cider vinegar, sugar, Dijon mustard, salt, and black pepper.
• Step 5: Add the slightly cooled potatoes to the skillet with the onions. Pour the vinegar mixture over the potatoes and gently toss to combine, making sure the potatoes are evenly coated.
• Step 6: Stir in the crumbled bacon and chopped parsley (if using). Serve warm or at room temperature.