INGREDIENTS
3
peeled and cut into 4 inch cubes 4 pounds russet potatoes
3
Celery, finely diced (about 1 cup), ribs
1/4 cup
Parsley, fresh leaves
1
Red onion, finely diced (about 1/2 cup), medium
4
Scallions
1 1/4 cups
Mayonnaise
2 tbsp
Mustard, whole grain
1
Black pepper, Fresh ground
1
Kosher salt
1/4 cup
Sugar
6 tbsp
Rice wine vinegar
1/4 cup
Chopped cornichons (see note)