SERVES 4

In the words of a French bistro owner, "Leeks have all the advantages: They are nourishing, cheap and tasty." If you happen to be making stock anyway, cook the leeks in it, instead of in water, for 6–8 minutes, thus benefiting both stock and leeks.

8 medium leeks
Salt
2 tsp. dijon mustard
5 tbsp. red wine vinegar
Freshly ground white pepper
7 tbsp. peanut oil
8 sprigs parsley
1 hard-cooked egg, peeled and chopped (optional)

1. Trim leeks, removing tough outer leaves and all but about 4" of green part. Starting about 1" above root end, slice leeks lengthwise, but not all the way through. Open leeks like a book and wash well in cold running water to remove all sand and dirt. Set aside.

2. Bring a large deep skillet of salted water or stock to a boil, add leeks, and simmer over medium heat until soft but not mushy, 6–8 minutes. Transfer leeks to a large bowl of ice water to stop them from cooking further. Carefully split leeks completely in half lengthwise and transfer to a rack, cut side down, to drain thoroughly.

3. Whisk mustard, vinegar, and salt and pepper to taste together in a small bowl. Gradually add oil, whisking constantly, until vinaigrette is smooth and creamy. Adjust seasonings and set aside. Remove leaves from 4 of the parsley sprigs, chop, and set aside.

4. Divide leek halves equally among four warm salad plates, arranging them in circles. Drizzle vinaigrette over leeks and sprinkle with egg (if using) and parsley. Garnish each plate with a sprig of parsley.