Place potatoes in a medium size pot and cover with cold water and bring to a boil. Cook for about 10 minutes until tender. Drain and place in a large bowl.

Meanwhile, cook the bacon in a fry pan until crispy. Remove with a slotted spoon onto a paper towel lined plate. Add the onions to the bacon grease and cook for 3 minutes. Add the vinegar and mustard and cook for another 2 minutes. Remove from heat, mix in the oil, and pour over the warm potatoes.

Season with salt and pepper. Add the green onions, parsley, and cooked bacon. Toss it all together and serve. This dish can be serve hot, room temperature, or cold.