In a saucepan add the potatoes and a pinch of salt. Cover with cold water. Bring to a boil over high heat, then reduce heat to medium-low and cook until potatoes are easily pierced by a fork and pulled out with little resistance, about 5 to 7 minutes.
Drain well and transfer the potatoes to a mixing bowl. Place in the refrigerator to cool completely.
Add the celery, garlic, dijon mustard, mayo to the potatoes and mix well. Season to taste with salt and pepper.
Mix in the parsley and serve or cover and refrigerate until you’re ready to serve.