1-Cut potatoes into 3/4-inch chunks. Place them in a large pot with 2 teaspoons kosher salt and cover with cold water by about 1 inch. Bring to a boil over high heat, then reduce to a gentle simmer. Cook until fork-tender, about 8-10 minutes.

2-While potatoes cook, prepare the dressing. If using eggs, peel and dice them. Dice the pickles and celery, then mince the shallot and slice the scallions if included. Finely chop the herbs. In a medium bowl, combine the diced eggs, pickles, celery, shallot, scallions, herbs, 1/2 teaspoon kosher salt, mayonnaise, Dijon mustard, and 1 tablespoon vinegar. Stir everything well to mix.

3-Drain the potatoes thoroughly and spread them in a single layer on a rimmed baking sheet. Sprinkle the remaining 1 tablespoon vinegar evenly over the hot potatoes. Let them cool to room temperature, which takes about 15 minutes.

4-Add the cooled potatoes to the bowl with the dressing. Fold gently to combine without breaking the chunks. Taste and season with more salt and black pepper as needed. Cover and refrigerate for at least 1 hour, or up to 1 day, before serving.