Boil potatoes in their jackets until tender.

Peel and slice the boiled potatoes.

Cut bacon into small pieces.

Cook bacon in a pan until almost done.

Add chopped onions to the pan with the bacon.

Cook until the onions are softened.

Add sugar to the bacon and onion mixture.

Stir continuously to prevent caramelization.

Pour vinegar into the pan all at once.

Cook until the sauce thickens.

Pour the bacon-vinegar mixture over the sliced potatoes.

Season with salt and pepper to taste.

Serve warm or cold.