Roasting is one of the easiest ways to cook vegetables. The dry heat encourages browning, creating aromatic compounds and toasted flavors. A toss with oil and salt beforehand is sometimes all that's needed to round out the results.

But while it seems simple, there are a surprising number of variables to roasting vegetables. From cauliflower to carrots, each has a different form, water content and density—meaning each can require different prep, roasting time and temperature. We wanted a singular go-to reference for perfectly roasted vegetables.

So we prepared nine common vegetables, measuring everything from time and temperature to the amount of oil and salt. We started with common weights—a medium butternut squash, for instance, weighs about 2 pounds—and basic cuts, using 1-inch pieces in most cases. Some items needed only trimming. We tossed all the vegetables with varying amounts of olive oil and salt, then roasted them on low-rimmed baking sheets. We gauged tenderness and browning to determine the timings.

While the results were fairly straightforward—producing roasted vegetables our kitchen was happy to snack on—we did make some crucial notes along the way. For pan prep, we skipped parchment or foil. The former can burn in high heat and the latter caused sticking. A metal spatula was the best tool for flipping and stirring, which prevents scorching the pan. But stirring didn’t benefit all the vegetables. Leaving some undisturbed actually led to better browning, as with the sprouts.

Minding the vegetables’ structure was important. Sturdier items like broccoli developed better color at higher temperatures; they also required less attention under the high heat. More delicate vegetables such as green beans fared better at a slightly lower heat and required closer monitoring.

Finally, when determining doneness, insert a paring knife into large pieces to check for tenderness, but be sure the vegetables have browned as well. Some items, like potatoes, soften early on but aren’t truly done until they’re brown and crispy.