I Could Eat the Whole Bowl Mustard Potato Salad

1 1.5-pound bag Melissa's baby red potatoes
4 ribs celery, diced
1bunch scallions (about five), diced
1/2 cup chopped parsley
2 hard-boiled eggs, chopped
3 Tablespoons cider vinegar
1/2 cup Duke’s mayonnaise
1 tablespoon Grey Poupon
Salt and freshly ground black pepper, to taste

Halve potatoes. Boil 10 minutes; drain. Place potatoes, celery, scallions, parsley, and eggs into a large bowl. Pour vinegar over top;  toss. Mix mayonnaise and mustard together in a small bowl; fold into potato mixture. Salt and pepper generously. Refrigerate for 1 to 2 hours to meld flavors. Serve.