1Combine the dill, vinegar, mustard, salt, and a pinch of black pepper in a small bowl. Stir to combine, then whisk in the oil until thick and emulsified. Set aside.
2Put the whole potatoes in a large sauce pan and cover generously with cold water. Add a big pinch of salt and bring to the boil over high heat. Reduce the heat so the water’s at a steady simmer, and cook until the potatoes are cooked but not falling apart (check by piercing a potato with the tip of a small knife), about 25 minutes. Drain and spread the potatoes out in a single layer to cool until they’re easy to work with, about 10 minutes.
3Cut the warm potatoes in half lengthwise and place in a large bowl along with the cucumber slices and red onion. Add the dressing, stir to coat well, and serve immediately.
Finding the absolute best ingredients such a big part of Chef Antoine Westermann’s culinary career and the main drive behind all of his expertly crafted dishes. His relationship with farmers and purveyors are critical to his work as a chef. While visiting one of his providers in New York, the French chef describes his efforts to find the best local ingredients for his restaurant.