Cut the potatoes into ½ inch pieces. Place in a large saucepan, and cover with water. Add two teaspoons of salt. Bring to a boil, then reduce to a simmer. Cook for 10–15 minutes, or until a fork slides through the potatoes easily.
Drain the potatoes and place in a large bowl. Let cool slightly.
Chop 2 of the hard boiled eggs, and add those to the potatoes, along with the celery, pickle relish, green onions, and red pepper.
In a medium bowl, whisk together the mayonnaise, mustard, celery salt, and vinegar.
Pour the mayonnaise mixture over the potato mixture, and toss gently with a spatula to combine. Refrigerate until ready to serve. Top the salad with the remaining hard boiled egg (sliced).
You can substitute chopped pimento peppers (from a jar) in place of the red pepper, if you'd like. You can also substitute sweet pickle relish for the dill pickle relish, and white vinegar for the apple cider vinegar.Purchase peeled hard boiled eggs from the grocery store to make this recipe even easier.You can make the potato salad up to 2 days ahead. Store in a covered dish in the refrigerator. Serve any leftovers within 5–6 days after making it.