Wash the potatoes in cold water, put into a pot with enough water to cover amply, cover, and bring to a boil. Cook until tender, then drain. Peel the potatoes as soon as they are cool enough for you to handle. Slice them thin after they have cooled off a little longer so that you can cut them into compact slices. If they are too hot, the slices will crumble.
Put 2tablespoons of the olive oil and the diced bacon in a skillet and turn on the heat to medium high. Brown the bacon, turning it from time to time, but do not let it become crisp.
Pour the entire contents of the pan over the potatoes together with a sprinkling of salt. Toss well and allow to rest before serving for at least 1 hour or up to 4 to 5 hours at room temperature.
When ready to serve, add the remaining 2tablespoons of olive oil and the chopped parsley, and toss well.