Sometimes you just want a roast chicken. It seems a bit incongruous for this classic cold-weather comfort meal, which invariably ends up as a simmering soup, to appear on a summer table. But sometimes you just want a roast chicken. As the old saying goes, “In for a penny, in for a pound,” so we went autumnal for this dinner — roasting sweet potatoes and cabbage alongside the chicken. The plate was beautifully colorful, filled with superfood nutrients, and the bone broth we made the following day from the chicken carcass, while steamy, filled our freezer with an elixir that...