In an oven set to 375 F, cubed potatoes and cut carrots can roast to completion in one hour. However, at a higher temperature, such as 450 F, they are done within 40 to 45 minutes.
Almost all vegetables can be roasted to create a caramelized exterior and intensified flavor. According to Better Homes & Gardens, a particular advantage to roasting is the freedom it gives the cook to prepare a combination of vegetables that may not all yield good results with other techniques, such as boiling or steaming. However, it should be noted that green and non-root vegetables, such as broccoli and green beans, may discolor or dry out at such high temperatures.