In a medium stockpot, cover potatoes with water. Bring to a boil. Once boiling turn down the heat to medium-high and cook for 30 minutes. Must be fork tender, if not sure cook for 5 minutes. Drain water and set potatoes aside to cool. (Cool for 45 minutes)

While potatoes are cooking, hard boil eggs in a sauce pan. Cover eggs with water. Bring to boil and cook for 12 minutes. Drain water and then put eggs under cool water until they are cool enough to peel.

While eggs and potatoes are cooking, chop onion, celery, and parsley. Add into a large mixing bowl wit mayo, mustard, salt, pepper and garlic powder. Chop eggs and potatoes once cool and mix into the salad.