Roasted Cauliflower and Broccoli Soup
Roasted Cauliflower and Broccoli Soup is incredibly simple but tastes so good. With a smooth, silky texture, it’s full of flavour without heavier ingredients like cream found in many versions. In fact, I think this pared-down recipe which allows the vegetables to shine, might be THE BEST Roasted Cauliflower and Broccoli Soup. To make it extra special, add optional garnishes like crispy greens and chopped nuts.
Jump to Recipe
LIGHTER CAULIFLOWER & BROCCOLI SOUPS
Everyone knows that the slightly peppery tastes of cauliflower and broccoli have an affinity with cheese and creamy things. In fact, before the advent of cauliflower ‘rice’, the only thing most Brits probably ever did to a cauliflower, other than boiling it to death, was making cauliflower cheese. But you can take it too far, as evidenced by the dominance of very creamy and cheesy cauliflower and broccoli soups.
A few years ago, I posted my own recipe for Roasted Cauliflower Soup. But even then, I preferred to dial it down by using more stock than milk.
Nowadays, I like it even lighter. So my latest version ditches the milk completely and also the potato I used as a thickener.
In their place are broccoli for extra flavour and nutrition, plus optional tasty garnishes including crispy greens.
ROASTED CAULIFLOWER AND BROCCOLI SOUP
The first time I made this Roasted Cauliflower and Broccoli Soup, I couldn’t believe just how tasty it was. Even without all the extras like cream and bacon found in many versions, it really was full of flavour. It also still had a smooth, silky texture. In fact, I think this economical version is the BEST I’ve had!
INGREDIENTS
As well as one small head of cauliflower and one small head of broccoli, you’ll need just a few more everyday ingredients.
- Olive oil and butter. For roasting, sautéing, and flavour.
- Seasonings. While salt and pepper are indispensable, I’ve also added a hint of dried thyme and ground cumin. But you can swap in almost any others, or just leave them out: the soup will still be tasty.
- Onion and garlic. Together they make the savoury base of the soup.
- Stock. I prefer chicken, but you could use vegetable.
OPTIONAL GARNISHES
For me, what can turn a good soup into a great soup are the garnishes. The following are just suggestions so pick as many or as few as you like.
For smooth soups, I like at least one crispy or crunchy garnish. While croutons are the obvious candidate, there is a lighter, no-carb alternative. And that’s fried shredded greens. If your cauliflower and/or broccoli came with some nice leaves still attached, you can use those. Mine didn’t, so I used kale leaves. Whichever you have, simply shred the leaves and quickly fry in hot oil. After draining on kitchen paper, I like to toss with a pinch of salt.
Other possible garnishes for Roasted Cauliflower and Broccoli Soup include:
- Toasted hazelnuts. Add more crunch and compliments the roasted veg. I buy in bags ready toasted and chopped.
- Toasted sesame seeds. For more nuttiness. I always keep a handy jar of home-toasted black and white sesame seeds in the cupboard.
- Flavoured oil. To drizzle over. If you’re using nuts or seeds as a garnish, then it’s nice to use a matching oil. Here I’ve used sesame oil, but hazelnut, walnut or pumpkin would all be good.
- Chilli flakes. Adds to the warming, cosy feel of the soup.
- Cheese. Although I’ve limited the dairy to just butter, cubes of cheese melting in each bowl are good if you want to up the protein. I would use a mature Cheddar or good quality blue cheese.
HOW TO MAKE ROASTED CAULIFLOWER AND BROCCOLI SOUP
You’ll find ingredient amounts and full instructions in the recipe card at the end. But read on for extra tips and step-by-step images.
While roasting cauliflower and broccoli deepens their flavour, in this case it doesn’t pay to get them too charred. That’s because if you allow them to get very dark then your soup will end up bitter.
Cut into florets, place on a baking tray (lined if not non-stick) and toss with olive oil, salt, pepper, and any additional dried herbs or spices. Transfer to the oven preheated to the temperature shown in the recipe card until lightly charred at the edges.
While that’s happening, you can be softening the chopped onion and garlic in more olive oil plus a little butter. Then, when the cauliflower and broccoli are done, tip those into the onion and garlic.
Now we stir in the stock. As tastes will naturally vary as to how thick we want our soup (and some ‘small’ heads of cauli and broccoli will be smaller than others), I suggest you start with roughly 750 ml and add more later if necessary. As a guide, make sure all the vegetables are more than covered to start with.
The pot is then simmered, with a lid on. If you’re making the crispy green leaf garnish, you can be getting on with that during this stage.
When the vegetables are soft, go in with a stick blender to whizz the soup to a very smooth puree. If it’s thicker than you like, add more of the stock. Finally, have a taste and add more salt and pepper if you think they’re needed.
SERVING ROASTED CAULIFLOWER AND BROCCOLI SOUP
For my Roasted Cauliflower and Broccoli Soup, I like a little of all the garnishes, usually except the cheese. I start with a pile of crispy leaves, then scatter toasted hazelnuts over. Next, it’s sesame seeds and mild chilli flakes. Finally, I add a swirl of sesame oil.
I love the flavour of the simple but deeply savoury vegetables transformed into this silky-smooth soup. Add to that the crispy, crunchy, little bursts of flavour from the garnishes, and I think you have something very special.
Without any garnishes, the cooled soup will keep for a couple of days covered in the fridge. As there’s no milk or cream to split, I suspect it would be fine to freeze too.
If you’ve made this easy, economical and delightful soup, do leave a comment and rating to let me know what you thought.
Roasted Cauliflower and Broccoli Soup
A simple soup that's full of flavour and with a smooth, silky texture.
Unlike many cauliflower and broccoli soups, it doesn't contain heavier ingredients like cream but allows the vegetables to shine.
To make it extra special, choose some or all the optional garnishes like crispy greens and chopped nuts.
Ingredients
- 1 small head cauliflower
- 1 small head broccoli
- 2 tbsp olive oil
- salt
- black pepper
- 1 tsp thyme (optional)
- ½ tsp ground cumin (optional)
- 1 large onion (roughly chopped)
- 4 large cloves garlic (finely chopped)
- 20 g butter
- 750 - 1000 ml stock
Garnishes (optional: choose all or a selection)
- crispy fried leaves from the cauliflower or broccoli, or kale/cabbage (see Recipe Notes)
- chopped toasted hazelnuts
- toasted sesame seeds
- chilli flakes
- flavoured oil e.g. sesame, hazelnut, walnut.
- cheese, cubed or grated
Instructions
-
Preheat the oven to 220°C /200° Fan /Gas 7 /425°F.
-
Break the cauliflower and broccoli into medium sized florets.
Tip: if they have leaves, you can shred and fry until crispy to garnish the soup.
Place on a large baking tray (non-stick or lined with baking paper) and drizzle with ONE tablespoon of the olive oil, a little salt and pepper, plus the thyme and cumin if using.
Put in the oven and roast until just tender and lightly charred: don't let them get too dark or the soup could be bitter but do turn up the heat if necessary.
-
While the cauliflower and broccoli are roasting, put the remaining tablespoon of olive oil in a saucepan over medium heat and add the butter.
When hot, stir in the chopped onion and garlic, a little salt and pepper, and cook until lightly browned and starting to soften.
-
Stir the roasted veg into the softened onion and garlic.
Stir in approximately 750 ml of the stock or enough to more than cover the vegetables and bring to the boil. Turn down the heat to a simmer, put on a lid, and cook until the vegetables are soft.
-
Use a stick blender to whizz the soup to a smooth puree. Add more stock if necessary to get your preferred thickness.
Taste and add more salt and pepper if needed.
-
Serve with any or all the suggested garnishes.
Soup can be cooled and stored in the fridge for 2 days or frozen.
Recipe Notes
For crispy leaf, kale or cabbage garnish. While the soup is simmering, heat a bland oil such as sunflower in a small saucepan or deep frying pan to high heat: be sure not to have it more than one third full. Shred the leaves and dry on kitchen paper if wet. If a leaf immediately sizzles when dropped in the oil, then it's hot enough. Fry the leaves, in batches if necessary, until crispy: this should take just a few seconds. Drain on kitchen paper and toss with a little salt if liked.
MORE SOUP & STEW RECIPES
