Peel potatoes, cut in 1 inch cubes, cover with cold water in large pot and bring to a boil.
Simmer 12-14 minutes or until potatoes are fork tender.
Drain well, return pan to stove and over low heat shake pot until excess water has evaporated. You want the potatoes dry and fluffy but don't let them stick.
Season lightly with salt and pepper and let cool.
Meanwhile, in large mixing bowl combine peeled and diced eggs (reserve one for garnish), onion, mayonnaise, mustard and pickle relish.
Add cooled potatoes and gently fold into mayonnaise mixture until well-combined.
Taste and adjust seasonings, add more mayonnaise if too dry, more mustard and/or relish to suit your taste.
Smooth top of potato salad, garnish with reserved egg cut into quarters as shown. Sprinkle with paprika and black pepper if desired.