For the dressing:
- 1/2 cup mayonnaise
- 2 tablespoons whole grain mustard
- 2 tablespoons cornichons, finely chopped
- 1 tablespoon brine from cornichons
- 2 teaspoons white wine vinegar
- Kosher salt
- Freshly ground black pepper
For the salad:
- 1 pound baby potatoes
- 3 stalks celery, cut into 1/4-inch slices
- 2 tablespoons chives, chopped
- 2 tablespoons dill, chopped
- In a medium pot, boil potatoes in heavily salted water until fork tender, about 15-20 minutes. Once cooked, cut any larger potatoes in half.
- Meanwhile, combine mayonnaise, whole grain mustard, chopped cornichons, brine, and vinegar in a small bowl. Season to taste with salt and pepper.
- While potatoes are still slightly warm, transfer into a large bowl. Toss with dressing, then let completely cool.
- Add celery, chives, and dill and mix well. Serve immediately or can be made 1 day ahead, covered and refrigerated without celery, chives, and dill.