Lightly poached leeks get dressed in a mustardy vinaigrette chock full of minced shallot in this classic French dish that doesn't get nearly enough play in the U.S. It's elegant, delicious, and can be made before the guests get anywhere near the doorbell. That's why I love to make this as a first course for dinner parties—it can be all ready to go hours ahead of time.
These leeks work well with chicken and fish dishes of all sorts, but if you follow French tradition and serve them as a separate first course, they go with pretty much anything! I've been known to serve them more as a salad with great success, so don't feel constrained by tradition.
- Cut off and discard the root ends of the leeks. Cut off the dark green tops (I like to cut just above where the leeks turn from light green to dark green, so a bit of that contrast makes it into the final dish). Discard the green tops or save them to use in broth/stock or in these dumplings.
- Take a good look at the leeks: is there much dirt between the leaves? Cut the leeks in half lengthwise from the top of the white part up through the light green part. Leave most of the white part alone, so the leeks hold together. Clean the cut-open leeks under cool running water. If you see any bits or patches of dirt, now is the time to rinse them away!
- In a large shallow pan, bring 1/2 inch water to a boil. Add 1/2 teaspoon of the salt. Add the leeks, laying them in the water. Cover, reduce heat to maintain a steady simmer and cook until tender, about 10 minutes (time will vary depending on the thickness of the leeks).
- Remove the leeks from the water and let them cool and drain on a clean kitchen towel or layers of paper towels. Squeeze out any excess water as you remove them from the pan.
- While the leeks cool a bit, peel and mince the shallot. Put it in a measuring cup or bowl with the oil, vinegar, mustard, remaining 1/2 teaspoon salt, and pepper to taste.
- Put the leeks on a serving platter or individual plates. You can leave them long, finish the lengthwise cuts to make them easier to handle, or chop them up—how you present them is up to you! Top the leeks evenly with the vinaigrette. Let them sit at least 30 minutes and up to several hours. The flavors will keep blending beautifully.