Boil largely diced potatoes and eggs in a large soup pot until potatoes are tender. (about 10-15 minutes) Allow to cool.
Chop scallions and celery. Once eggs have cooled, peel the shells and rinse with cool water. Chop the eggs.
Mix together mayonnaise, sour cream, mustard, salt and pepper.
Add potatoes, eggs and scallions. Mix together until completely covered with sauce.
Top with shredded cheddar cheese and bacon bits.