In a large pot of water, add potatoes and bring water to a boil.
Boil potatoes until fork tender, approximately 30-40 minutes depending on the size of the potatoes. Drain water and let potatoes cool.
In a large bowl, add in mayonnaise, mustard, relish, chopped hard-boiled eggs, salt and pepper. Stir until combined.
When potatoes are cool, cut potatoes into 1 inch cubes and place into the bowl.
Stir to fully coat potatoes with the mayonnaise mixture.
Season with additional salt and pepper to taste, if desired.
Garnish with sliced green onions.