Boil the potatoes in salted water until tender, about 15 minutes. Drain and let cool.

In a mixing bowl, combine the cooled potatoes, chopped eggs, celery, and green onions.

In a separate bowl, mix mayonnaise, mustard, vinegar, salt, and pepper to create the dressing.

Pour the dressing over the potato mixture and stir gently to combine.

Chill in the refrigerator for at least 30 minutes before serving.