Roasted Cauliflower & Leek Soup

This cauliflower leek soup is easy to make, but you'd never guess it from the taste - roasting & blending the veggies makes it flavorful & satisfying.

Roasted Cauliflower & Leek Soup

Thank you all SO much for your ideas & suggestions of what to make with my giant cauliflower. You had so many creative ideas, and I just loved reading through them all.

Last night, we curled up on the sofa with this creamy roasted cauliflower & leek soup. (Note: I used cashews for the cream part – if you’re nut-free, check out this creamy vegan cauliflower soup recipe.) This process might look subtle, but roasting the cauliflower, leeks & garlic brings out some pretty big flavors… and in a surprisingly little amount of time. The short version of this recipe is this: Roast. Blend.

(But I promise, it tastes fancier than that).

Roasted Cauliflower Leek Soup

Thanks to so many of you for commenting with the leek & cauliflower soup idea… I went with this cashew cream idea suggested by Alisa. With the “toss it all in the oven” method (and paprika addition) as suggested by Anouk.


4.9 from 18 reviews

Roasted Cauliflower & Leek Soup

 
This creamy vegan cauliflower leek soup is a breeze to make - just roast & blend! I love it with a hunk of crusty bread on the side.
Author:
Recipe type: Soup
Serves: 3 as a main, 4-5 as a starter or side
Ingredients
  • About 2 cups chopped cauliflower
  • 2-3 leeks, white and very light green parts, chopped (about 1 to 1½ cups)
  • 2 garlic cloves
  • Extra-virgin olive oil, for drizzling
  • ½ cup raw, unsalted, un-roasted cashews, soaked overnight* (see note)
  • 1½ teaspoons miso paste (or just salt if you don't have any)
  • Leaves from a few sprigs of marjoram or thyme
  • 3 cups water
  • 2 tablespoons more olive oil (to blend into the soup)
  • ⅛ teaspoon smoked paprika (or more to taste)
  • Squeeze of lemon
  • Sea salt and fresh black pepper
  • Red pepper flakes (optional)
  • Splash of white wine vinegar or champagne vinegar, at the end (especially if you made yours too spicy like I did)
Instructions
  1. Preheat the oven to 400 degrees. Spread the cauliflower, leeks, and garlic on a baking sheet. Drizzle with olive oil and sprinkle with a few pinches of salt & pepper. Roast for 20-30 minutes, rotating halfway through. Remove when everything is starting to turn golden, but before the leeks are burning (if a few get too charred, it's ok, just pick them out later).
  2. Add to your blender the veggies you just roasted, drained cashews, marjoram leaves, miso paste, a squeeze of lemon and 1½ cups water. Blend until pureed. Add the 2 tablespoons olive oil, paprika, and the remaining 1½ cups water. Blend again. Taste and adjust seasonings.
  3. Pour into a medium saucepan and heat just until the soup is warm. Stir in a little more water if it's too thick. Serve with bread on the side.
Notes
*Be sure to use plain raw cashews or your soup will taste too much like cashews. If you're using a high speed blended (vitamix or blendtec), you could get away with soaking your cashews for less time because the blender will liquify everything thoroughly anyway.

 

84 comments

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  1. Sue L
    01.27.2021

    Hi,
    Just made this soup and amended it a little based on what I had on hand. I roasted 3 parsnips and added them to the blender along with almond-cashew milk. Also added a tbsp of maple syrup, half a teaspoon of mustard and a teaspoon of tamari in addition to the miso. Delicious!

  2. Jeannie
    01.11.2021

    Hi! Do you have nutritional information for this recipe?

  3. Colleen
    11.05.2020

    Made this with purple cauliflower. Soup had a funky color but was delicious! I substituted homemade chicken stock for the water.

  4. Sarah
    04.14.2020

    400 degrees!!!! My oven only goes to 250 degrees. 400 degrees will set you house on fire in seconds.

    (yes I know this is more than likely 400 degrees Fahrenheit. please remember the world outside of America uses Celsius – you don’t want people misreading and setting their house on fire)

  5. C.F.
    11.01.2019

    This is delish! Do you think it would freeze well? I made a big batch and have a lot leftover, but we have lots of evening plans coming up and I don’t think we’ll have a chance to finish it…

  6. Nikky
    09.05.2019

    I just made this and it was SO excellent!! I don’t have an immersion blender or a fancy ninja-like blender so I did have to blend it in my regular blender for a long time and add an additional 3/4c of liquid (I used half veggie stock, half water), but it still turned out with an amazing thick and creamy texture without being chunky! Patience totally paid off, so anyone else out there using a regular blender, dont give up! Also didn’t have the vinegar, but I didn’t miss it. Another delicious recipe Jeanine!

  7. Roxy b from roxyborger.com
    06.04.2019

    Yum! Really good flavor and good balance of comforting yet not too heavy. I ended up needing 1c more water (I actually used homemade veggie broth). Thanks for great recipe.

    • Jeanine Donofrio
      06.07.2019

      Hi Roxy, I’m so glad you enjoyed the soup!

  8. Carina
    05.08.2017

    Yes!! this looks and sounds so delicious and it’ll be dinner tonight, I just put the cashews in to soak 🙂 Thank you.

  9. Amber
    03.09.2017

    I made this for dinner last night. I could not believe how easy it was! I did not remember the cashews in time though, and I only have a Ninja (not the blender, the ice crusher/food processor) so I skipped that part. But put in half a cup of almond milk. It was super delicious! And since I’m sick, I used 6 cloves of garlic. It wasn’t overpowering. I’m so glad I made this! Thank you!

  10. Miriam
    01.07.2017

    I tried this today and it was delicious! I served it with a little white truffle oil on top – it was a match made in heaven! Thank you for this lovely recipe 🙂

  11. Sue-Ann
    01.07.2017

    What a happy way for a cauliflower to be eaten!! Cashews definitely added to the joy! I served mine with sliced chorizo sausage that I cheerfully roasted with the cauliflower (local supermarket makes a good chorizo) instead of adding the paprika. Can’t you just feel my happiness through the screen?!?!!!!

  12. Kenzee
    01.06.2017

    Hi! This recipe looks delicious and I want to make it very soon, however, I am someone who cannot eat any nuts. What would you suggest I substitute in place for the cashews? Thanks in advance 🙂

  13. Just made this! Doubled the ingredients and added (canned) coconut milk, coriander, and a lot more lemon juice. I poured it over some cooked red potatoes and it was so wonderful. Thanks!

    • Jeanine Donofrio
      12.31.2016

      So glad you enjoyed it!!

  14. Fiona Mackay
    12.08.2015

    Great for using the cauliflower and 2 leeks from my veg box, which have been sitting in our fridge for weeks. As partner has a nut allergy, was sorry to omit the idea of yummy cashew cream. Was going to use (probably not quite so suitable ) sunflower seeds, instead, but this soup still tastes creamy, silky and delicious without them.

  15. Victoria
    11.27.2015

    I made this as a starter for Thanksgiving. It was fabulous! I multiplied the recipe using 3 heads of cauliflower, 7 leeks plus two regular onions and 2 cups of raw cashews to serve 20 people. I cut and roasted the veggies when I put the cashews in to soak, so all I had to do was whir it up in the blender the next day. Delicious, though it looked like cream of mushroom soup. Only change was to use homemade veggie broth instead of water. That may be why the soup was brownish.

    The acidity of lemon was crucial. The soup was rich but not heavy, well seasoned yet subtle. I used enough chili flakes to give it heat but not to make it spicy. Perfect for a lactose and gluten free offering and well received by everyone including kids. I garnished each bowl with a few leaves of thyme and some of the smaller bits of roasted cauliflower florets.

  16. This is going to be a perfect recipe to try when the leeks are ready in my garden! I love to use raw cashews for cream, frosting….you name it, they can do it! Beautiful photos! I hope to one day reach this level with my photography!

  17. Pey-Lih
    03.03.2015

    This soup looks so delightful! I will make it this weekend. My husband and I have tried a few of your recipes and they have turned out wonderful. So glad I found you through C+K. And Kate is awesome, too!

  18. Holly
    02.28.2015

    This was really good! Thanks for the recipe. I just ran it on high in the Vitamix to heat it up…one less pan.

  19. J
    02.20.2015

    If I use dried thyme or majoram how much should I use? 1 tsp?

    • jeanine
      02.20.2015

      I’d maybe start with 1/2 teaspoon (you could always add more to taste), or you can skip it if you want. The miso and the paprika will give it plenty of flavor.

A food blog with fresh, zesty recipes.
Photograph of Jeanine Donofrio and Jack Mathews in their kitchen

Hello, we're Jeanine and Jack.

We love to eat, travel, cook, and eat some more! We create & photograph vegetarian recipes from our home in Chicago, while our shiba pups eat the kale stems that fall on the kitchen floor.