How To Roast Vegetables
(with AND without oil)

Learn how to roast vegetables so they are perfectly cooked. We make it EASY for you with one cooking time and one oven temperature. Foolproof perfection!

So I used to use oil for roasting, which is why I started using this technique less and less as we have naturally turned to using less oil in our cooking over here.

Then one day I thought "Do I HAVE TO use oil when roasting? What happens if I don't?" And thus, the super-sleuth investigation began, per usual.    :)

How To Roast Vegetables

Let's begin by first talking about what exactly it means to roast vegetables?

Historically, to make roasted veggies you toss them with some olive oil and seasoning, and then place them in a high-heat oven. As they cook, the outside of the veggies form a bit of a "seal" while the insides become tender and the natural sweetness of the vegetable comes out.

Sounds delicious doesn't it? That's because it is!

You can still do things the "traditional" way, use oil.

But I'm going to teach you how to make oil-free roasted vegetables too because after our side-by-side comparison of those cooked with oil and those cooked without, we preferred the latter hands down. But there are some special instructions when roasting without oil, and we'll cover both ways (oil and oil-free) below.

First, though, here's the quick answer to the actual HOW to roast your veggies...

  • Pre-heat your oven to 375 degrees F
  • Clean and prep!
  • Cook all veggies uncovered for 45-60 minutes
  • Stir/flip your veggies a few times while they cook

Now, if you search around the 'net, you'll find all sorts of advice about the various cooking temperatures and times for roasting vegetables. But we're going to keep things VERY simple for you by teaching you how to prep veggies so they ALL cook at 375 degrees for 45-60 minutes.


So you don't have to stop to say to yourself "Ummmmmm, okay....what was the temperature -- and cooking time -- of THIS PARTICULAR VEGGIE?!" Who needs that when you're running around like a chicken with your head cut off to get dindin on the table? Just remember 375 degrees for 45-60 minutes uncovered. That's really all there is to it.

But there ARE some particulars you need to know so everything goes smoothly...

The Type Of Dish To Use

My preference is to use my large 13- by 9-inch glass baking dish (my lasagna pan). But if I'm making less veggies, I might use my glass pie dish.

The most important thing in choosing your dish is to remember that it needs to be big enough. How big is "big enough"? Just large enough so the food can have a little "breathing room". Never smoosh them together so tightly in a dish that the heat won't be able to get at all sides of the veggie properly or they won't cook evenly.

Some people prefer to line their dish with parchment paper because it makes for an easier cleanup.

Personally, I don't like to line my dishes with parchment because one of the things that make roasted veggies so good is the caramelization that occurs where the vegetable meets the dish. Veggies roasted with parchment DO (indeed) caramelize, just not as much as those cooked in a dish NOT lined with parchment.

There is a distinct difference between veggies cooked on parchment and those cooked directly on the glass surface. You can see that difference in these pictures...

Those cooked directly on the glass dish have more of the "roasted look" (and taste!) we all love.

So the choice is entirely yours whether to cook with parchment or without. The other factor to take into consideration is the "sticking" factor if you're not using oil, and we'll cover that below.

But don't worry, because no matter which way you go, your roasted veggies will be deeeeelicious.

Prepping Your Vegetables

Remember I said we're going to teach you how to prep your vegetables so they are all done in the same amount of time? Here are the factors to take into consideration...

Choose your veggie -- how hearty is the one you want to cook?

Think about asparagus, which is likely one of the most delicate veggies out there. It's okay to leave them whole because the heat of the oven can easily make it through from the outside all the way to the inside.

Another of the more delicate veggies is zucchini and other summer squash. These are very easy to cut and pretty tender in the raw state, so these can be cut into fairly large chunks.

Then consider veggies like broccoli, cauliflower, and cabbage. These are not as delicate as asparagus or zucchini, but they're not super dense either. They fall in a "mid range" of veggies. I would never put an entire head of these guys in the oven. But you don't need to cut them into teeny tiny pieces either. Usually cutting them around 2-inches or so should be sufficient for the heat of the oven to penetrate and cook them evenly.

And finally we have the more dense vegetables like carrots, potatoes, turnips, and beets. If they're hard for your knife to cut through, it's hard for the heat of the oven to get through as well. So for these guys you should cut them into 1/2- to 1-inch cubes so the heat can easily penetrate to the middle. Really, the smaller the better. Or, be prepared to cook them for a longer amount of time.

Sassy Sez: I have known people who want to leave dense veggies like this in a larger cut (like quartered) so they parboil them first to get the insides cooking and then finish off in the oven.

But I don't like this technique. Why, you ask? Because then they are not TRULY roasted.

I mean, the whole point of roasting is to cook them at high temps so the outside gets sealed while the inside cooks (think of a baked potato). If the outside has already begun the cooking process, then it is going to be more difficult to get that seal on your veggie. Make sense?

Alternatively, as mentioned above, you can keep these cuts larger and simply turn the heat up higher and cook them longer. That works too!

What I'm teaching you here today is how to cook all your veggies at the same temperature for the same amount of time just to keep things simple.

The size of the chop makes a difference.

As with most cooking techniques, always be sure your "chop" is approximately the same size so they cook in the same amount of time. For instance, if I'm cooking potatoes, I'm not going to have some cut in 1-inch cubes while some are 3-inch cubes. They all should be approximately the same size.

Of course, if you're cooking more than one type of veggie at the same time, you don't want them all the same size. You will still follow the chop recommendations above, keeping in mind the difference between the delicate, mid-range, and heartier veggies.

For instance, if I'm cooking zucchini, broccoli, and sweet potatoes together, I will cut the zucchini in large chunks, the broccoli in about 2-inch pieces (about the size of the floret), and the sweet potatoes into 1/2- or 1-inch cubes.

Onions and tomatoes are special. They cook fairly quickly and are pretty watery. So you can almost always keep their chop on the large side, such as quartering them. When roasting tomatoes, always use a baking dish with sides in case the juices run amuck.    :)

If You Use Oil...

...which I really don't recommend since there's no reason to, and it's not exactly good for you.

But IF you do...

A little oil goes a LONG way.

I cringe when I see people pouring a boat load of oil over their veggies before roasting. OMG! So unnecessary!

Here's how to use less oil...

Begin by placing your veggies in a large bowl. Start with 1/2 teaspoon of olive oil and drizzle over the top. Then toss with your hands to ensure all the veggies get coated - using your hands it becomes very obvious which need more attention.

The more veggies you have, the more oil you might need. But always add more in just 1/2 teaspoon increments.

Add veggies into your preferred baking dish.

If You're Oil-Free...

You have TWO choices when it comes to roasting your vegetables.

The EASIEST way to roast without oil is to add veggies into your preferred baking dish, then very lightly mist with a little water so the seasonings adhere. So easy and healthy, guys!

The SECOND way to roast without oil is a little more high maintenance but it will ensure your veggies don't dry out which can sometimes happen when using no oil and no broth. Place your veggies into a large bowl. (If you have just washed them and they're wet, allow them to sit for a bit to get rid of some of the excess moisture.) Next, drizzle 1 teaspoon of vegetable broth over the top and toss with your hands. Add more veggie broth by the teaspoon, tossing each time, until all the veggies get coated. We start with 1 teaspoon because everyone is working with different amounts of veggies—plus, some veggies will soak up more broth (like broccoli) than others (like squash). It's important that you don't saturate your veggies with the broth.

When all veggies seem to be coated with the veggie broth add veggies to your preferred baking dish. (If you accidentally overdid it with the broth you can pour veggies into a colander to ensure all the veg broth gets poured off before baking but hopefully you won't need this extra step.)

As I mentioned, the biggest difference I have found between roasting with the light mist of water and roasting with the veggie broth is the broth veggies might be just a tad more on the moist side and the non-broth are just a little drier. Experiment with both and see which you like best: Do you need it to be easier to make? Or do you prefer your veggies to be more moist?

Using herbs and spices.

First, use the "basics," sea salt (try kosher salt which is more coarse) and freshly ground black pepper.

But beyond that, you can use ANY dried herbs and spices you like. This is what really makes YOUR roasted veggies unique.

Be sure to check out the Flavor Matches located throughout our site to get ideas for which herbs and spices and other flavorings are a good match for your veggie of choice.

You might stumble upon a combination of seasonings that will become your "signature," and that your friends will be dying to know about. Whether you choose to share your secret is completely up to you.    ;)

Roasting Your Vegetables

As mentioned above, place your dish of veggies in a preheated 375 degree F oven.

Set the timer for 10 minutes.

After 10 minutes is up, remove your dish from the oven, and flip and turn the vegetables. This ensures they all cook evenly PLUS the veggies won't stick too badly when the cooking process is complete. The "10-minute mark" at the very start of cooking seems to make a difference to the "stick factor". You DO NOT have to do this initial 10-minute step if you use parchment paper, but you will still have to stir/flip occasionally.

  • If Using Oil: Place the dish back in the oven for another 35-50 minutes until cooked through, stirring occasionally. And that's it. Enjoy!

  • If Using No Oil AND No Broth: Place the dish back in the oven for another 35-50 minutes until cooked through, stirring occasionally. And that's it. Enjoy!

  • If Using Broth: Place the dish back in the oven for 10 more minutes.

When the time is up, remove the dish from the oven again. This time we're going to "baste" the veggies with a little of the extra broth, one teaspoonful at a time.

The goal is to ever-so-slightly cover the veggies with the broth. You don't need a lot -- our goal is not to steam them! Just to moisten them a little so they can continue roasting without drying out.

Continue cooking for the full 25-40 minutes, stirring occasionally, adding a little veg broth as needed. Enjoy!

You'll get to know which veggies need the full 60 minutes, and which only need 45 to be cooked to your liking. Whichever timing you choose, remember to stir and flip the veggies occasionally -- and baste, for oil-free.

Hope you have enjoyed this little tutorial. Please leave any questions or comments below.

Happy cooking!

p.s. Oil-free cooks, here are more tips you'll love...

"I love your site. It is so full of valuable info. I have been vegetarian all my life (59 years) and my husband has been veg since he was 10 (when he discovered Thanksgiving dinner entree was his pet goat!)."
-- Charlene Blanchard, Lehigh Acres, Florida

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