To get nice, crispy caramelization on roasted vegetables, simulate the intense heat of an industrial oven: Bring your oven up as hot as it goes, then put an empty roasting or sheet pan inside for 10 to 15 minutes. Toss the vegetables — try carrots or Brussels sprouts — with olive oil, salt and pepper, and put them on the hot pan. This method will give you the high heat you need to caramelize the sugars in the vegetables quickly.