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 26 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.
Recipe type: Soup
Serves: 3 as a main, 4-5 as a starter or side
  • 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)
  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.
*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.



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Rate this recipe (after making it):  

  1. AP

    It was okay. Reasonably sort of pleasant but pretty bland and almost bitter… cauliflower needs a real flavour expert working with it in terms of how to combine things in a soup or it runs the risk of tasting a little bitter. Would not make it again tbh. Sorry but wanted to be honest. 3 stars was being generous…

  2. Wendy

    I would like to try this for a dinner party… can I do steps 1 and 2 mid day and leave the soup in the saucepan until dinner time? I’ve not cooked with cashews before so wonder how well they will ‘sit’. Thank you.

    • Phoebe Moore (L&L Recipe Developer)

      Hi Wendy, yep, you can make the soup ahead! I’d keep it in the fridge and reheat just before serving.

  3. Rachel Cantin

    Not my favorite, but still good!

    • Phoebe Moore (L&L Recipe Developer)

      Hi Rachel, glad you enjoyed it!

  4. Corina Greegor

    This was so delicious! My hubby and boys said it tasted like baked potato soup and they gobbled it up! I made it a second time and couldn’t use cashews because my mom has a nut allergy and she was eating with us so I subbed in white beans. It worked! Creamy and so yummy. Thanks for a keeper!

  5. Susan

    Excellent! I used veggie broth instead of water.

  6. Keryn

    Hi, it doesnt say what to soak the cashews on, milk, water and how much? Do you drain after soaking and how many hours?

    • Phoebe Moore (L&L Recipe Developer)

      Hi Keryn, Soak them in water for 6-12 hours. The exact amount of water doesn’t matter as long as the cashews are fully submerged. Drain before blending. Hope this helps!

  7. Sarah

    It was delicious! We have loved it, only added chicken broth!

    • Phoebe Moore (L&L Recipe Developer)

      Hi Sarah, so glad you loved it!

  8. Elissa

    Help! I love the taste of the soup but my texture did not come out smooth. I’ve been blending in my Ninja blender. Is this not powerful enough? I strained a little bit of the soup but lost most of the bulk of the soup. Any suggestions?

    • Phoebe Moore (L&L Recipe Developer)

      Hi Elissa, It’s probably just the blender! We love using a Vitamix for pureed soups like this.

  9. Denise Wood

    Hi Jeanine!

    I only have dried thyme on hand… any suggestion on amount to add?


    • Jeanine Donofrio

      Hi Denise, I’d do 1/2 to 1 teaspoon.

  10. Wonderful soup!
    The paprika and miso added nice flavour too. I blended in some white beans for protein. Thanks!

  11. Diane

    This was delicious, the roasting brings out so much flavor, and makes it all so easy! I didn’t have cashews this time (but we’ll try next time), used homemade broth instead of water, and threw in a pablano pepper on the roasting pan and used my immersion blender. Rich flavor! I recommend it!

  12. Taps

    What’s the best way to thicken up the soup if it’s too watery? I didn’t have cashews, so I substituted coconut milk, but didn’t change anything else from the recipe. The taste is delicious, but a little loose for my taste.

  13. Alex

    I just made this soup and it was so delicious! I forgot to add the vinegar and chilli but was still delicious without. Fussy hubby enjoyed it too. Will definitely make again!

  14. Jules

    Absolutely delicious! Thank you.

  15. Sasha

    Can I substitute half and half for the cashews? I want to make tonight so no time to buy and soak the cashews.

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.