Boil potatoes in their jackets until tender.

Cool the potatoes, then peel and dice them into bite-sized pieces.

Hard boil 3 dozen eggs until fully cooked.

Cool the eggs, then slice them.

Dice the celery stalks and onions.

Chop the parsley.

In a large bowl, combine the diced potatoes, sliced eggs, diced celery, diced onions, and chopped parsley.

Fry the bacon until crisp.

Remove the bacon from the pan and crumble it.

In a separate saucepan, combine the well-beaten eggs, sugar, dry mustard, salt, pepper, and vinegar diluted with cold water.

Mix well to combine.

Pour the egg mixture into the hot bacon drippings in the pan.

Stir constantly over medium heat until the mixture thickens, about 20 minutes.

Pour the hot egg mixture over the potatoes and mix lightly to combine.

Add the crumbled bacon and celery seed.

Serve hot or cold.