Ingredients

6 medium leeks (about 2 1/4 pounds)

2 tablespoons olive oil

1 tablespoon grainy mustard

1 teaspoon Dijon mustard

2 teaspoons white-wine vinegar

Salt and pepper

Preparation

Trim tough, dark greens from leeks; discard. Halve leeks lengthwise, and cut off root ends, leaving as much of bulb intact as possible. Rinse each half under running water, carefully separating layers to loosen dirt.

Place a steamer basket over a saucepan filled with water; simmer. Prepare a large bowl of ice water.

Place leeks in steamer basket, cover and steam, until very tender, 10 to 12 minutes. Transfer to bowl of ice water to cool; drain. Dry on paper towels, cut side down, patting gently.

In a small bowl, whisk oil, mustards, and vinegar; season with salt and pepper. Arrange leeks on a platter; spoon vinaigrette over top.