Less Waste When Prepping
I like to roast asparagus because the method allows me to cook enough to feed my large clan and requires very little hands-on attention. My usual approach couldn’t be simpler: Toss the spears with some oil, salt, and pepper; spread them on a baking sheet; and pop them into a 400-degree oven until they are deeply browned—the hallmark of any good roasted vegetable.
But while the outcome has been good enough, I have always had a nagging sense that it could be much better if I concentrated on figuring out the ideal recipe (and made it foolproof while I was at it).
I was already aware of one downside to roasting: Unlike heartier vegetables such as cauliflower or potatoes, which can withstand longer roasting times to develop good color, slender asparagus spears often overcook by the time they brown, giving up their fresh flavor and tender snap and trading their grass-green color for a duller shade of army fatigue.
To nail the ideal—spears that are both crisp-tender and well-browned—I had to start with the right size asparagus. I was pretty sure that thicker specimens (at least ½ inch in diameter) would hold up better to the heat than the pencil-thin kind. Roasting a bunch of each size according to my usual method provided confirmation, as the skinnier spears practically wilted by the time they were sufficiently roasted. They were also comparatively chewy, thanks to their higher ratio of fibrous skin to tender flesh.
With thicker spears, the question was how to remove their woody stems: Should I trim them with a knife or snap them off at the spears’ so-called natural break point? I tested both methods on multiple asparagus bunches and realized that using a knife was the way to go because it produced less waste. Then, to remove the remaining tough outer skin, I grabbed a vegetable peeler and stripped the stalks down to their creamy white flesh—a step that added a few minutes to the prep but maximized the stalks’ tenderness as well as their visual appeal
Back to the cooking method. Recipes that I found called for a wide range of oven temperatures (from 350 to 500 degrees) and cooking times, but since I already knew that the spears were taking too long to brown at 400 degrees for 12 minutes, I set my sights on a hotter oven. Sure enough, when I tested different roasting temperatures at various time increments, the batch I blasted at 500 degrees for no more than 10 minutes was the best: bright with a tender snap.
But unfortunately the degree of browning was only fair. The leap I wanted to make for color development was essentially the difference between a moderate sauté and a hard sear—and once I thought about it that way, the problem became obvious. I was starting the asparagus on a cold baking sheet. The better plan would be to preheat the sheet in the oven on the bottom rack (closest to the element) so that the spears would essentially sear upon contact. This change made all the difference; the next round of testing offered up spears with flavorful but spotty browning.
I knew I was on the right track, but when I retested this method, I made one useful mistake. Midway through the roasting time, I shook the baking sheet to ensure that the spears browned evenly on all sides. The resulting spears were indeed evenly browned, but not deeply browned. For the next test, I resisted the urge to shake the sheet, leaving the spears to cook undisturbed, and the results were the best yet: vibrant green on one side with a deep, flavorful sear on the other. Tasters didn’t seem to mind that the spears weren’t evenly browned.
As good as this asparagus was, I wanted to develop some quick seasonings to give the dish more variety. Fresh garnishes would enhance the stalks’ vibrancy, so I whipped up a gremolata, the Italian minced-herb condiment usually made with lemon zest, garlic, and parsley. But instead of the classic profile, I took a broader approach and came up with variations that traded the lemon zest for orange or lime zest and some of the parsley for mint, tarragon, or cilantro.