This sauce in this recipe is essentially a half batch of Roasted Garlic Cauliflower Soup. You can make this dish in a snap by making a full soup recipe and freezing it in portions. Defrost in the microwave when you’re ready to make mac and “cheese.” You can use the sauce straight up over pasta, but to make this a more balanced meal, we’ve suggested the hunger-quenching add-ins of beans and kale.