16 baby leeks, rinsed well
2 tbsp sherry vinegar
1 tsp Dijon mustard
Pinch of sea salt
Pinch of freshly ground pepper
1 ½ tbsp minced chives
1 tbsp minced fresh chervil or flat-leaf parsley, plus whole leaves for sprinkling
½ cup peppery extra-virgin olive oil
Trim the root ends from the leeks, leaving just enough attached to keep the leeks from falling apart.
In a rectangular glass baking dish, combine the vinegar, mustard, salt, pepper, 1 tbsp of the chives, and the minced chervil. Whisk together until well blended. Add the olive oil in a slow, steady stream and whisk to blend. Place the leeks in a the dish and toss to coat them well. Cover the dish with plastic wrap and marinate the leeks at room temperature for at least 1 hour or refrigerate for up to overnight.
About 15 minutes before you plan to serve the leeks, prepare a medium-hot fire in a grill.
Remove the leeks from the marinade, shaking off any excess, and reserve the marinade. Arrange the leeks on the grill rack and cook until tender and nicely browned, 5 to 6 minutes, turning occasionally to cook them evenly.
Transfer the leeks to a warmed platter and drizzle lightly with some of the remaining marinade. Sprinkle with the remaining chives and the chervil leaves. Serve hot or at room temperature. Serves 4.