Wash and scrub the potatoes, then place them in a pot of generously salted water.

Boil the potatoes until tender (about 15 to 20 minutes), then drain and let cool slightly before cutting them into bite-sized cubes.

In a medium pan, cook the bacon until crispy, then remove and let drain on a paper towel. Chop into small pieces.

In the bacon grease, sauté the chopped onion until soft and translucent (about 5 minutes).

Add the apple cider vinegar, mustard, sugar, salt, and pepper to the pan.

Whisk in the olive oil until smooth.

Toss the warm potatoes with the dressing and stir in the chopped bacon. Garnish with fresh parsley if desired.