Active Time

　　15 min

　　Total Time

　　30 min (includes hard-boiling egg)

　　Mâche is sold in different ways — sometimes it comes in a package with soil plugs attached and sometimes you can find it loose, like mesclun. If you're buying it with plugs attached, you'll need 1 1/2 pounds; if you're buying it loose, you'll need 5 ounces.

Ingredients

　　1 yolk from a large hard-boiled egg

　　2 3/4 teaspoons white-wine vinegar

　　1 teaspoon Dijon mustard

　　1/4 teaspoon salt

　　1/8 teaspoon black pepper

　　1/4 cup olive oil

　　16 cups loosely packed mâche (lamb's lettuce; see above)

Step 1

Step 2

　　Cooks' note:

　　Vinaigrette can be made 1 day ahead and chilled, covered. Bring to room temperature, then whisk until combined well.