8 small leeks, about 500 grams
Salt and pepper
2 tablespoons Dijon mustard
1 tablespoon red wine vinegar
3 tablespoons extra virgin olive oil
2 teaspoons capers
8 to 12 gherkins
2 hard-cooked eggs, halved lengthwise
Trim leeks, removing tough outer layers and cutting off root ends. Leave a little green at the top. Make a lengthwise slit part way down each leek. Put leeks in a large basin of warm tap water and swish vigorously to dislodge any sand or dirt. Remove carefully, leaving grit in basin.
Fill a medium sauce pot with water and bring to a boil. Add a generous pinch of salt and put in leeks. Cook at a brisk simmer for 8 to 10 minutes, until leeks are quite tender when pierced with a paring knife. Drain and cool to room temperature.
Make vinaigrette: put mustard and vinegar in a bowl and stir to dissolve. Whisk in olive oil to make a thick sauce. Season with salt and pepper.
Blot leeks and divide among 4 plates. Spoon vinaigrette over leeks, smearing with the back of a spoon. Sprinkle with capers. Garnish each plate with cornichons or gherkins, olives and half an egg.