I love broccoli. I really, really, really do. Which is why I don’t understand how so many people want to muck up good broccoli soup by adding a bunch of potato to it.
Now, granted, I’ve had good broccoli potato soup once or twice, always with more broccoli than potato in it. But even then, the fuzzy heaviness the potato gives just isn’t my thing. I’m always hesitant to order broccoli soup in restaurants, because it so often comes with a sludgy, slightly grainy potato base. Which is why, when I was craving a thick, pale, slurpable broccoli soup recently, I turned to cauliflower instead.
I just love what cauliflower does when it meets hot liquid and a blender. When pureed, it turns almost starchy, but with a lightness that starch just can’t match. I’ve used it as a potato replacement in soup before, with roasted garlic and red lentils, but this might be my new favorite mutation. Broccoli and cauliflower are cousins, so it only makes sense that they would play well together–bold and brassy versus subtle and sweet. Mixing them together creates an almost airy soup, comforting yet light, perfect for sipping out of a mug.
This is a soup that evolves over time. Immediately after blending, it’s loose and flowing, pale minty green, and the flavors are bright and clean. As it sits, it thickens slightly and darkens somewhat, and the flavors mellow and blunt a bit. Refrigerate it or freeze it, and it loses some of its invigorating freshness, becoming milder and subtler.
That’s fine by me, because a soup like this is best treated as a blank canvas. When it’s freshly made and crisp-flavored, a drizzle of olive oil is all it needs. But now that I’m working my way through my freezer stash, I’m taking the opportunity to play. So far, I’ve had leftover soup with a squeeze of fresh lemon and a handful of grated Parm; with a drizzle of toasted sesame oil and a squirt of Sriracha; and, tonight, with a dab of harissa and some feta cheese crumbles. All of my adaptations so far have been fantastic, and all dramatically different. I love that so much.
Cauliflower Broccoli Soup (serves 6)
Inspired by Gordon Ramsay
2 tbsp olive oil
2 medium leeks, white and light green parts only, washed and thickly sliced
2 large or 4 small garlic cloves, peeled and lightly crushed with the back of a knife
6 cups water
1 1/2 lb cauliflower (about 1 medium head), cored and chopped
12 oz broccoli florets (from about 1 medium bunch)
Freshly ground black pepper or white pepper to taste
In a large heavy-bottomed pot, heat oil over medium-low heat. Add leeks, garlic, and a pinch of salt; reduce the heat to low and cook, stirring frequently, for 10-15 minutes, or until the leeks are very soft.
Add water, increase the heat to medium-high, and bring to a boil. Add cauliflower and a large pinch of salt. Bring the water back to a boil, then reduce the heat to low, cover, and simmer for 15-20 minutes, or until the cauliflower is very tender.
Increase the heat to medium-high, and bring the water back to a rapid boil. Add broccoli florets, cover, and cook for 4-5 minutes, or until the broccoli florets are tender and the cauliflower is falling apart. Turn off the heat and puree with an immersion blender, or in batches in a stand blender. (Let it blend for a while–you want the soup as smooth as possible.)
Season the soup with salt and pepper to taste. Ladle into bowls, and serve warm. Leftovers will keep in an airtight container in the fridge for up to 3 days, or in the freezer for up to 6 months.