In the non-summer months, the ideal vegetables for oven roasting are root vegetables, particularly potatoes, turnips, carrots, and onions (and you might also throw in some parsnips). You don't even have to peel them first, but they do roast more uniformly if you parboil them. Do that for about 15-20 minutes, then drain and cool them. Chop them into large chunks, toss them in some olive oil, salt and pepper, and roast them at 400 degrees for about a half hour or until they begin to turn slightly crispy and golden brown on the outside. They're the ideal accompaniment to roasts of any sort.