Fast, simple method
In the past I rarely, if ever, cooked broccoli rabe. (Rabe, or rapini, as it’s known in Italy where the vegetable is a mainstay in the cuisine, is actually more closely related to spicy turnips than to regular, more-mellow broccoli.) While I’m a fan of this green’s bitter, mustardy bite, I seem to be in the minority on this. As a result, the majority of recipes you find jump through hoops to subdue its characteristic flavor. One of the most popular approaches calls for chopping, blanching, shocking, draining, and sautéing the pieces with strong-flavored aromatics—a lengthy ordeal that wipes out just about any trace of the green’s pungency and leaves you with a sink full of dirty dishes. At that point, why bother?
I’ve always thought that if you could temper rabe’s bitterness but not eliminate it entirely, this green would offer much more character than most vegetables. As a bonus, it would need little or no dressing before it hit the plate. The trick would be figuring out the most efficient way to do this.
I made some headway by researching where broccoli rabe gets it bitter flavor. The technical explanation is that when the plant is cut or chewed and its cells thus damaged, two components stored mainly in its florets—the enzyme myrosinase and a bitter-tasting substrate of the enzyme called glucosinolate—combine, and some of the glucosinolates are converted into even harsher-tasting isothiocyanates. In other words, the pungency we taste is the plant’s defense mechanism when under attack.
Nipping Bitterness in the Bud
Cutting and chewing broccoli rabe releases compounds that are bitter. Since more of these compounds are in the florets, we leave the leafy part whole. Broiling the rabe also reduces bitterness, as heat exposure deactivates the enzyme (myrosinase) that causes the bitterness.
The upshot was that the way in which I cut the rabe seemed likely to be at least as important as how I cooked it. I proved this to myself with a quick side-by-side test: I divided a bunch of rabe in half and fully chopped one portion, florets and all. Then, I cut the remaining stalks roughly where the leaves and florets start to branch off from the stems, leaving the leafy parts intact, and cut the stem segments (where less of the enzyme resides) into bite-size pieces. For the sake of ease, I simply sautéed both batches and took a taste. Sure enough, the intact pieces were considerably more mellow. It also turns out that there was another factor at play: The high heat of cooking deactivates the myrosinase enzyme in the vegetable and thus stops the reaction that contributes most of the bitter flavor in the first place.
I could have stopped right there and created a recipe for sautéing chopped stems and whole leaves and florets, but I’d found a few recipes that called for roasting the rabe, which was an interesting alternative. Plus, I hoped that the rabe would brown deeply and take on a rich caramelized flavor that would balance out the remaining bitterness. I prepared another batch, giving the stalks a quick rinse before cutting them using my new technique; tossing them with extra-virgin olive oil, garlic, red pepper flakes, and salt; spreading them on a rimmed baking sheet (which was big enough to arrange them in an even layer); and sliding the sheet into a 400-degree oven.
After 10 minutes, the rabe had caramelized nicely, and the leaves now also offered a delicate crunch—that part was good. But texturally, the stems had suffered, turning soft and stringy by the time they had browned.
Part of the problem, I realized, was that the water droplets left over from washing the rabe were taking a long time to burn off and therefore delaying browning. Going forward, I got serious about drying the greens by rolling them in clean dish towels to blot away as much moisture as possible. I also cranked the heat to 450, but even then the stems were limp by the time they were browned.
It was time to take it up a notch to the broiler. I adjusted the oven rack 4 inches from the heating element, popped in another oiled and salted batch, and kept a close watch. In less than 3 minutes, half the rabe’s leaves and florets were lightly charred and crisp at the edges, and the stems were also browned yet still bright green and crisp—so far so good. I gave them a quick toss with tongs and slid the sheet back into the oven. Two minutes later, the results were perfect: lightly charred, crisp leaves and florets and perfectly crisp-tender stalks.