Start by placing your firm Yukon Gold or red potatoes in a large pot, covering them with cold water. Bring to a gentle boil and cook for about 15 minutes, or until tender but still firm. Drain and cool slightly.

In a mixing bowl, whisk together the vegetable broth, apple cider vinegar, and Dijon mustard. Add sugar, salt, and pepper to taste.

Cut the cooled potatoes into bite-sized pieces and add them to a large mixing bowl along with the chopped onion and chopped celery.

Pour the prepared dressing over the potato and vegetable mixture, gently tossing everything together without mashing the potatoes.

Stir in the chopped parsley for added flavor and color. Let the salad rest for at least 10 minutes before serving.