Frozen Cauliflower is a member of the cruciferous vegetable family along with Brussels sprouts, cabbage, broccoli, collard greens, kale, kohlrabi, rutabaga, turnips and bok choy. cauliflower — a versatile vegetable. Eat it raw, cooked, roasted, baked into a pizza crust or cooked and mashed as a substitute for mashed potatoes. You can even prepare cauliflower riced as a substitute for regular rice.