Wash potatoes and place in a pot, add water to cover and bring to a boil. Lower heat to medium-high and cook just until fork tender. Do not overcook!
Place hot potatoes into cold water to cool. Using a sharp knife scrape skins off potatoes and rinse. Into a large bowl, dice into 1" pieces. Add chopped eggs and pickles, toss lightly using a large cooking spoon.
In a pile add mayo, mustards, onions and remaining ingredients. Use a folding motion to combine them. Once combined, continue to fold into the potatoes and eggs.
Refridgerate immediately and for at least a couple of hours before serving.