Step 1: Cook the Potatoes: Place the cubed potatoes in a large pot and cover with cold water. Bring to a boil, then reduce heat and simmer until tender, about 15-20 minutes. Drain well.
Step 2: Cook the Bacon and Onions: While the potatoes are cooking, cook the diced bacon in a large skillet over medium heat until crisp. Remove the bacon with a slotted spoon and set aside, reserving about 2 tablespoons of bacon fat in the skillet. Add the chopped onion to the skillet and cook until softened and translucent, about 5-7 minutes.
Step 3: Prepare the Dressing: In a small bowl, whisk together the apple cider vinegar, sugar, Dijon mustard, vegetable oil, and chicken broth.
Step 4: Combine and Season: Add the drained potatoes to the skillet with the cooked onions and bacon fat. Pour the vinegar dressing over the potatoes and gently toss to coat. Season with salt and pepper to taste.
Step 5: Finish and Serve: Stir in the cooked bacon and fresh parsley. Serve warm or at room temperature. For best flavor, allow the salad to sit for at least 30 minutes before serving to allow the flavors to meld.
For a tangier flavor, increase the amount of vinegar. To make it vegetarian, omit the bacon and use olive oil instead of bacon fat. A pinch of celery seed can enhance the savory flavor.