February 4, 2009 | Technique, Vegetables

Ah, the simplicity of the humble leek. Never heard of it? Don’t know what to do with it? And wondering why you should bother to read more about the leek in this post? Let me give you the run down and see if I can pique your interest.

The leek is a member of Alium family (onion genus), but it has a milder oniony flavor and cooks up softer because it’s thinner. It grows in a tall stalk with a white bulbous based and green leaves that darken the further up the stalk you go. I’ve been getting tons of them from the farm during the winter harvest share, so I’m using them up in various recipes.

Begin by lopping off the roots at the base and peeling away any outer damaged layers. Next cut off the dark green tops of the leeks – it’s OK to use the light green part, so use my picture above as a guide for the green color you’re looking to keep. Next, because leeks push their way up from the soil in a straight shaft, they collect a lot of dirt in the process. You’ll want to cut them in half lengthwise like I did above – see the specks of dirt hiding in there?
Next, chop them up and put the pieces into a strainer or colander under running water so you can work all of the pieces under the water and rinse out the dirt. (My hands look horrible – I need to start using cream!) Some people prefer to put them in a big bowl of water to soak and let the dirt sink to the bottom, but for me the running water works better.

After cleaning the leeks and patting them dry, they are ready for cooking. Saute them in a skillet with a little extra virgin olive oil and/or butter plus a sprinkling of salt and pepper. They’ll soften faster than a thick onion so keep your eye on them.

Leek and Gruyere Tart
Serves 6-8

6 ounces flour
4 ounces butter, cold
2 ounces water
1 teaspoon vinegar
2 cups diced leeks, sauteed until soft
6 ounces grated Gruyere cheese
8 whole eggs
2 cups half and half (or whole milk)
salt and pepper

Cut cold butter into cubes. With mixer on low, add butter to flour and mix until crumbly. Mix water and vinegar together, then slowly add to mixer on low just until dough begins to come together, discarding any unused water. Shape dough into a ball and cover with plastic wrap; refrigerate for 1 hour or up to 1 day. (TIP: I always make my dough for the crust the day before. I often make a couple and keep them in the freezer.)

Preheat oven to 375 degrees F. Remove dough and let stand still wrapped in plastic for 15 minutes at room temperature before rolling out on a lightly floured surface. Shape into an 11″ tart pan with a removable bottom, discarding any leftover scraps of dough. (Or nibbling on them if you’re me.)

Place tart pan on a baking sheet. Spread leeks and Gruyere cheese evenly over the bottom of the tart crust. In a large bowl, beat eggs together lightly, then add half and half, and season with salt and pepper. Mix well with a whisk. Gently pour egg mixture on top, being careful not to overfill. Place tart in the oven and bake until lightly golden on top and a toothpick comes out clean, about an hour. Let cool slightly before removing outer rim from tart pan and serving.