There is no great secret to roasting vegetables; simply cut them into equal-size pieces for even cooking, toss in ghee or oil, season with sea salt, and roast in a tray that is not too crowded, at a temperature high enough to caramelize the sugars (over 330°F/165°C) until crispy edged and golden. The trick is to choose your vegetables wisely, those that can be transformed by the intense heat of a high-temperature oven: Brussels sprouts, broccoli, and cauliflower all become more nutty and sweet; the sweetness of caramelized beets and carrots blends perfectly with their earthy nature.