This uses the method at America's test kitchen; flat sheet under broiler method. It's a bit rough on the oven, but many ways to vary it up. There's a poblano, brown mushrooms and shallots in there; with turnips, carrots and beets. The bigger the carrot the better; little thin things burn up.
Looks good! One way to help keep the oven clean is making a foil tent with lots of holes. Heat and moisture vent through, and most of the splatter sticks to the tent. I'm assuming from the picture that an electric oven is being used. In a gas fired unit, there isn't enough clearance.