How to Make Restaurant-Quality Roasted Cauliflower Soup at Home

One of the wonderful things about cooking is how even a small change in technique can produce remarkably different results. In this smooth and creamy soup, that technique is the simple step of roasting the cauliflower before simmering and blending it, which adds a sweet and nutty dimension to the vegetable's otherwise mild flavor, making it feel just a touch more autumnal in that warm and comforting way.

This isn't my first foray into the world of puréed cauliflower, both roasted and not—I once published two recipes for cauliflower purée where roasting was the differentiating factor. At the time, I described my unroasted purée as silky and restrained, while the roasted version was more complex and nutty. But perhaps more relevant to this recipe is that I made clear that the difference between a cauliflower purée and a cauliflower soup is nothing more than thickness—the method for making each is the same, the only real difference is how much liquid you add to thin the puréed vegetables.

That's the beauty of understanding technique: Two things that might seem different reveal themselves to be almost exactly the same. This means that just about everything I said for those purée recipes applies here: You want to sweat your aromatics, then add the cauliflower and simmer it in a flavorful liquid like stock, and finally blend it all to a smooth and silky finish.

I only really have a couple important notes to add for this soup:

• Roast the cauliflower at very high heat, which ensures optimum browning. In this recipe, I make a point of cutting the cauliflower into relatively large florets. This helps preserve some of the more moist interior of the vegetable and avoids it drying out excessively in the oven during roasting while still exposing enough surface area for the oven's heat to brown the exterior well.
• The liquids are flexible, but try to use something flavorful and not just water. I think chicken stock works really well here, but anyone who wants to keep this vegetarian can use a rich vegetable stock instead. I also add cream for some extra richness, but if you'd like to make this vegan you can simply omit it and use more stock or broth.
• Pay attention to the soup's consistency and adjust accordingly. I deliberately start with too little liquid and then thin the soup more fully only after blending. I find that this approach ensures that every batch of soup ends up with the consistency you want while accounting for personal preference and variables like evaporation during cooking. If the soup is too thick (it will be), thin it with more liquid. You really shouldn't run into a too-thin issue with this recipe unless you accidentally over-dilute it, so...don't do that.
• I'd almost go as far as to say the garnish on a puréed soup like this one is as important as the soup itself, giving it a clearer identity and layering additional textures and flavors that the soup itself can't deliver. To give the relatively simple roasted cauliflower soup base here more interest, I garnish it with a whipped, curry-spiked sour cream. The spices work very well with the roasted cauliflower, while the sour cream's tang adds an important bright note. That said, you should feel free to experiment with other garnishes; they're an easy way to keep a soup like this feeling new and exciting even if you've been eating it for many days straight.

All in all, this is a soup that's easy enough to whip up on a weeknight, but also would feel very at home as a starter for a fall or winter holiday meal.