A broccoli floret may not look anything like a Brussels sprout, but they've actually got a lot in common. Both are members of the brassica family, along with a ton of other not-so-similar-looking cruciferous vegetables—cauliflower, cabbage, kohlrabi, kale, and more. And, just like Brussels sprouts, broccoli turns nutty, sweet, and delicious when roasted right—and unfortunately mushy and sulfurous-smelling when not.
To get the best results from roasting broccoli, cut the head into florets one and a half to two inches long. After tossing with olive oil, salt, and pepper, roast at extremely high heat (500°F/260 °C) on a preheated baking sheet for about 20 minutes total.
The Full Story
For decades, broccoli (and Brussels sprouts) suffered from a serious image problem, and poor cooking technique was often the culprit. When the level of heat used is too low and the vegetable is cooked too long, the sulfurous compounds inside have plenty of time to develop, leading to the smelly results that put many an American schoolchild off their cafeteria lunch.
But when you subject broccoli to super-high heat, it quickly caramelizes on the outside, producing sweet, nutty flavors and a crispness on the outside that contrasts nicely with the tender interiors of the florets. At that temperature, broccoli also cooks through fast enough that those less pleasant aromas don't have time to take over.
To get there, I preheat the oven to 500°F (260°C), with the oven rack in the top position. To speed up caramelization even further, I line a half sheet pan with foil, and pop it in the oven during the preheating stage. Meanwhile, I cut the broccoli into fairly small florets, about one and a half to two inches, which creates more surface area and therefore greater textural contrast.
I toss the broccoli with a little olive oil and season it with salt and pepper. When both oven and pan are blazing-hot, I carefully transfer the broccoli florets to the pan, and in they go to roast for about 20 minutes. For more even browning, you can flip the broccoli with a thin metal spatula about halfway through, or, if you prefer one side to be crispier and more deeply caramelized, just leave 'em alone for the entire cooking time.