3 cups diced peeled potatoes
4 slices bacon
1 small onion, diced
¼ cup white vinegar
2 tablespoons water
1 ½ tablespoons white sugar, or more to taste
1 teaspoon salt
⅛ teaspoon ground black pepper
1 tablespoon chopped fresh parsley
Place potatoes in a large pot and add water to cover by at least 1 to 2 inches; bring to a boil. Cook until potatoes are easily pierced with a fork, about 10 minutes. Drain, and set aside to cool.
While the potatoes are cooking, place bacon in a large, deep skillet over medium-high heat. Fry until browned and crisp, 10 to 12 minutes, turning as needed. Transfer bacon to a paper towel-lined plate and crumble when cool enough to handle. Leave bacon grease in the skillet.