Don't let the warm, orange color fool you; this is definitely cream of cauliflower soup. I like to leave the skin on my sweet potatoes because so many nutrients are lost when your peel them. The smoked gruyere really adds a creamy depth to the soup, as well. You may also want to top with toasted pine nuts to add a little texture, perhaps even some crispy bacon. Either way you serve, you will lick the bowl clean.