The Food Lab Thanksgiving Special: Braised Leeks with Parsley and Lemon
Birthday meals can be fancy. Christmas dinner? Sure—multi-course it up. Break out the truffles, foie, and suckling pig. But Thanksgiving dinner? It's all about simple, inexpensive ingredients treated right. Fall vegetables don't have the splash of summer vegetables or nice big winter roasts, but what they lack in showmanship they make up for in comfort.
Take leeks, for example. They're the archetypal wingman. They disappear into stews and soups and gently flavor sauteed vegetables. They melt into sauces and hide out in stir-fries. I mean, they even play second fiddle to potatoes, for god's sake. That's potato-leek soup, not leek-potato soup.
Well, Mr. Leek, November is your time to shine.
Unlike onions with their pronounced sweetness and pungent aroma, leeks are a far more mild vegetable. My favorite way to cook them as the main ingredient in a dish is to braise them. They retain their subtly aroma but acquire a completely tender, almost meaty texture as they slowly break down and absorb liquid.
Braising is a slow cooking process that is primarily used for relatively tough cuts of meat with a high amount of connective tissue like say, short ribs or chicken thighs. You brown them first in hot fat, then cook them slowly in a moist environment partially covered with liquid. The idea is that over time, the tough connective tissue will break down into rich, smooth gelatin, turning the tough cut tender and creating a rich jus to serve with it at the same time.
The same process can be used for vegetables, the main differences being temperature and timing. With meats, it's ideal to keep them in the 160 to 180°F temperature range. These relatively low temperatures prevent muscle fibers from tightening too much, helping the meat to retain more juiciness while simultaneously allowing connective tissue to break down.
Vegetables, on the other hand, must be cooked much hotter. Pectin, the structural cement that holds together vegetable cells doesn't begin to break down until 183°F, after which point, it breaks down fairly rapidly. Leeks braised in simmering liquid will cook in 30 minutes or less, rather then the hours it takes meat to braise.
Cut them in half lengthwise, and they form neat, simple serving portions that look pretty on a dish and are easy to handle in the pan. Splitting them also lets you rinse them—necessary to wash out any sand or grit that might be hiding out between the layers.
To heighten their sweetness a bit, it's best to caramelize their cut surfaces in hot oil before adding your liquid. Why the cut surface? Because it's easier to lay them flat that way. Even though only the edges will acquire any color, everything's cool—those wonderful browned compounds are water soluble, which means that after you add your liquid, many of them will dissolve and spread throughout the dish.
You can use any type of liquid you'd like, but I like to use a combination of white wine and chicken or turkey broth, along with a few nuggets of good butter. The butter keeps things lubricated while the leeks cook and will add richness to the sauce the leeks and stock form as it slowly cooks in the oven.
You can get all fancy if you want and transfer the braised leeks to a pretty serving platter, but with this kind of food, I'm perfectly happy with a handful of roughly chopped parsley, a sprinkle of lemon juice and zest, and some really good olive oil.
About the author: J. Kenji Lopez-Alt is the Managing Editor of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.