How to roast vegetables in an oven, without oil and more easy roasting tips

From asparagus to zucchini, roast vegetables perfectly every time with these simple steps and tips.
Roasted vegetables
Almost all vegetables are suitable for roasting. Claudia Totir / Getty Images
/ Source: TODAY

Craving cruciferous vegetables, summer squash or juicy tomatoes? Sometimes there's nothing better than a nutritious and delicious plate of roasted veggies.

When you're ready to roast, it's important to brush up on how best to prepare your vegetables of choice. TODAY food stylist and chef Katie Stilo shared her go-to prepping and roasting tips because nobody wants undercooked beets, overcooked zucchini or soggy green beans.

The first thing to consider when roasting is understanding what type of vegetable you want to cook. Root vegetables, for example, typically have longer cook times and often require a smaller dice. Some vegetables, like beets, can be wrapped in foil whole and and roasted until a knife easily pierces the center. Vegetables with a higher water content, like squash or eggplant, need a hotter oven and a shorter cook time, otherwise you'll end up with a dry, shriveled up side dish.

Once you've identified your preferred produce, follow Stilo's foolproof plan.

How to roast vegetables

1. Best vegetables to roast

When it comes to which vegetables taste best when roasted in the oven, it can be hard to choose the wrong one! Stilo uses the oven to make almost any vegetable. Carrots, broccoli, Brussels sprouts, cauliflower, any variety of squash, pumpkin, potatoes, onions, parsnips and beets.

The only veggies that don't roast well? If you're thinking about roasting delicate salad greens, like baby spinach or arugula, just don't.

Most veggies roast up well simply seasoned with just some olive oil, salt and pepper. You can always spruce up your veggies with a little bacon fat, just like Al Roker.

2. The basics of oven-roasting

Always make sure the oven is fully preheated before roasting, advised Stilo. About 375-400 degrees for root vegetables, and 400-425 degrees for veggies that have more water. If the oven is the wrong temperature, your cooking time might not yield the desired result.

"I like to preheat my tray in the oven while I prepare my vegetables," Stilo told TODAY Food. "This way, when they make contact with the tray, they instantly begin to sizzle and roast. I also don't use parchment (paper) when roasting my vegetables because I think it limits the browning you get on the surface of the vegetables."

Roasted Vegetable and White Bean Salad

To make sure her vegetables are evenly coated with oil and seasoning, Stilo tosses everything together in a bowl before laying them out on the tray. Don't overcrowd the veggies or the hot air won't circulate and the veggies will steam instead of roast.

"About every 10 minutes or so, rotate the tray in the oven so (all vegetables) are being evenly roasted. I also like to stir them around a bit using a spatula to make sure they’re crisping evenly and not sticking to the tray," Stilo said. "Some ovens have hot spots where one side cooks more than the others, which is why its always good to rotate your trays while roasting."

If you try to flip your veggies and they're sticking to the pan, it means they're not ready to flipped.

"Have patience and the veggies will respect you," Stilo said.

3. How to roast frozen veggies

Stilo advises following the same basic tips as you would with raw veggies when roasting frozen ones. That being said, because they have more water in them, they will likely steam before browning and will therefore take a little more time to achieve that an ideal roasted golden-brown color.

4. How to roast vegetables without oil

Roasting vegetables without seasoning is possible but not advised.

"Don't expect the veggies to get the same caramelization and browning as if you had used oil," Stilo told TODAY.

If you really don't want to use any oil, consider roasting the veggies on parchment paper or aluminum foil for easier cleanup. Make sure to flip them as you would any other roasted veggies.

5. How to roast root vegetables.

Root Vegetable and Feta Bruschetta

When you're rooting for sweet, tender root veggies, follow Stilo's instructions:

  • Put the roasting tray into the oven and preheat oven to 400 degrees.
  • Cut vegetables to desired size.
  • Toss cut vegetables in oil (if using) salt, pepper and any desired seasonings or herbs.
  • Spread out evenly onto baking tray, being sure not to overcrowd.
  • Roast in the oven, rotating ever 10 to 15 minutes. Toss vegetables with a spatula before placing tray back into the oven to ensure they are roasting evenly.
  • Roast until vegetables are browned and tender. The time will vary per type of vegetable, so keep your eye on them. A medly of vegetables like parsnips, onions, bell peppers and beets cut into about 1-inch pieces will take about 30-40 minutes.

6. How to reheat roasted vegetables

According to Stilo, there are several ways to get roast vegetables back to their deliciously crisp state. Put them back in the oven, spread them out evenly on a baking tray and reheat them for about 10 minutes. You can also throw them in a skillet with a little oil, add them into a stir fry recipe, or use an air fryer or a toaster oven until they're warmed through and slightly crisp.

Stilo advises against the reheating vegetables in the microwave, however, because they can get soggy and mushy.