Note: Sections of this recipe and text are excerpted from my upcoming book, The Food Lab, Volume II. For updates on the book and its release, please check my website, where you can sign up for my newsletter and find links to purchase my first book, The Food Lab: Better Home Cooking Through Science.
Back in college, when I used to cook dinner nightly for 45 people at my old fraternity house, haricots verts amandine—the classic French side dish of green beans with almonds—was a staple in my arsenal. Looking back, though, anyone versed in French cuisine would probably recognize it as only a pale shadow of the glory it can achieve when it's at its best.
I could blame my budget ($1.60 per person per meal meant frozen vegetables were the norm). I could blame my time constraints (two hours to shop and cook each day). I could even blame the kitchen (try cooking in a kitchen shared by 45 college students!). All of those things contributed to the dish's mediocrity, but the truth is, my green beans amandine were suffering primarily because I didn't really know what I was doing. My method? Defrost the green beans, briefly sauté some pre-minced garlic in oil, then toss it all together along with a bag of slivered almonds. Slide it all into the chafing dish, and turn my attention to the I-hope-it's-cooked-through-in-time chicken in the oven.
What I didn't realize was that this particular dish was ripe with learning opportunities. As is so often the case with simple preparations, the difference between mediocre and great all comes down to a matter of technique, and this one packs in quite a few. (Don't worry, they're all pretty easy.)
Technique #1: blanching. That is, par-cooking the green beans in salted water in order to tenderize them and set their color. As Daniel discovered through rigorous testing, most of the conventional rules of big-pot blanching are true. Dropping your vegetables into already-boiling water ensures that they cook rapidly and retain a bright green color, while salting that water adds some subtle seasoning (although he found that using a giant pot is not necessary). Transferring the cooked vegetables to ice water (or cold running water, at the very least) halts the cooking process to ensure that they retain a nice crunch.
In testing my recipe, I confirmed that blanching the green beans—a method that calls for completely submerging the vegetables and cooking all of them evenly from all sides—produces superior results to steaming, simmering in a saucepan, or cooking sous vide.*
*Note to self: Continue research to see if there's ever a time when it's worth cooking green vegetables sous vide in lieu of blanching. So far, the answer is no.
Technique #2: fat-toasting nuts. If you'd asked fraternity-house-cook-era me how to toast nuts, I would've said to put them on a tray in the oven until they're done. Ask me the same question now and I'd add three things to that list: dry-toasting in a skillet, dry-toasting in the microwave (my favorite way to dry-toast a small quantity of nuts), and slowly toasting them in hot fat. The latter method is the one I find myself using most frequently these days.
Toasting in fat offers a couple of advantages over dry-toasting. The first is even browning. Hot fat acts as a buffer, distributing the pan's heat evenly over the nuts, instead of just the bits that are in direct contact with the hot metal (the same principle explains why we add fat to a pan before sautéing or searing). With dry-toasting, it's very easy to accidentally burn part of a nut, while another bit remains completely raw. With fat-toasting, on the other hand, you can quite easily get the entire nut deeply browned. The second advantage is better flavor distribution. While the fat helps the nuts develop flavor, those nuts in turn impart flavor to the fat, for more even flavor distribution throughout the dish.
For this recipe, I toast slivered almonds in butter over moderate heat. As the nuts toast, the butter also browns, intensifying that nutty aroma. Which brings us to...
Technique #3: making a brown butter sauce. Transforming a pan full of toasted nuts and brown butter into a glossy sauce is relatively easy. First off, I add a little more flavor by sautéing some thinly sliced shallots and garlic, adding them to the skillet just as the nuts achieve maximum browning. (Don't worry, the shallots and garlic cool the pan down enough to prevent the nuts from burning.)
By the time butter browns, all of its water content has been driven off, leaving nothing but browned proteins and butterfat in the pan. This pure fat can have a greasy, heavy texture. To form a sauce, you need to add a water-based liquid with which it can form an emulsion. Lemon juice makes up one part of this liquid, brightening up the flavor of the sauce. I finish the sauce with just a small splash of water before increasing the heat to high and shaking the pan vigorously to encourage an emulsion.
This last technique—creating an emulsified sauce out of fat and water in a skillet—is one you'll use again and again once you get the hang of it. The key is to keep an eye on the sauce. If it appears watery and thin, there's too much water-based liquid in it; let it keep reducing on the stovetop, while vigorously shaking and stirring, until it becomes glossy and thickens slightly. If, on the other hand, it appears broken and greasy, there's not enough water in it; add a splash of water or stock, then shake and simmer like crazy until it re-emulsifies.
Once a glossy sauce has formed, all you've got to do is toss in the green beans and coat them in that toasty, nutty, garlicky, lemony stuff. Delicious.
The finished dish is still undeniably simple, yet elegant enough to serve in the most well-appointed of French bistros. Or even an undergraduate fraternity house. Just don't expect those students to pause long enough to thank you.** Have you seen college kids eat?!?
** Notable exception: My wife, Adriana, was one of those students, and she made a point of coming into the kitchen to thank me after every single meal. It's not the only reason I fell for her, but politeness sure does go a long way.