In order to prevent their surface from burning, what can be placed beneath vegetables to be roasted before placing them on the baking tray?
I am thinking of applying oil to the tray, but I'm not sure if that's enough.
I usually put tinfoil down and then lightly oil it. If done carefully, the tray stays clean and doesn't need to be washed and the foil can be thrown out (or used for a second batch of veggies if you have one).
You can avoid oil altogether if you cover your baking trays in parchment paper. Just make sure that you fit the paper to the shape of the tray and don't be surprised if the edges turn brown/black at higher (400 degrees and up) temperatures.
If you need help locating parchment paper, I would suggest visiting nearby restaurant supply stores, checking out your local supermarket (Reynolds has a brand of parchment paper available), or utilizing an online store such as Amazon or King Arthur Flour.
Oh, and one last thing: I recommend parchment paper because I used to volunteer as a prep cook and we would constantly use it to bake things like fish sticks, pizza pockets, and vegetables. Why? Because nothing got stuck on the pans, nothing got burnt, and clean up involved stripping off the paper, wading it up, and throwing it in the garbage. Now if that's not easy, I don't know what is.
I love using foil, but only for certain things. And now that I paid $9 for a large roll, I won’t use it as much anymore. It also tends to turn potatoes a bit grey and I can taste the foil.
The Irish girl that I am, I love using enamel roasting pans. Here is the trick, put the pan in the oven first to pre-heat. Then in a bowl add your potatoes (well rinsed), carrots (cut smaller) or mix in some sweet potatoes. Add your spices then oil and toss. In 10 mins when the pan is hot, pull out the rack with the pan, then throw in the mix. A lot of sizzling goes on. Halfway through the cooking process, toss the mix and cook some more, I always use loud timers. The potatoes don't stick or burn, unless your oven is too high or you leave them in too long. If they do stick towards the end, just pull it out and let the pan cool. The potatoes will then release on their own.
The great thing about enamel pans, they darken your potatoes and carrots to such a sweet flavor. Also, when they start to get a buildup you can throw them in your self-cleaning oven. Just lean it up on one side. Remember, your self-cleaning oven sides are enamel.