Place potatoes in a saucepan and cover with cold water by an inch. Place over high heat, bring to a boil, reduce the heat to a fast simmer and cook until fork tender, about 10 minutes.
While the potatoes cook combine the mayonnaise, mustard in a small bowl and reserve.
Drain the potatoes, return to the sauce pot and place back on the heat for one minute to cook off any residual water. Place dry potatoes in a bowl, add the cider vinegar, season with some salt and pepper, toss to coat and cool completely.
Combine the cooled potatoes with the mustard mayonnaise mixture and the remaining ingredients.