Vegan Roasted Cauliflower Soup with Potatoes, Lemon & Rosemary

Created by Laura Wright
4.83 from 28 votes

Vegan roasted cauliflower soup with potatoes, lemon, and rosemary is simple to make, super satisfying, and just so delicious.

An overhead shot of a bowl of vegan roasted cauliflower soup, garnished with croutons and chopped parsley. The soup is beige. The bowl is on a beige napkin, which is on top of a wooden cutting board.
An overhead, off-entered shot of a head of cauliflower in plastic wrap. The label says “Chou Fleur” in blue.


This vegan roasted cauliflower soup recipe is easy in many ways. There are 5 seasonal and accessible main ingredients. It’s just a roast and blend kind of affair, so there’s minimal hands-on time. A bowl is so warm and filling on its own, while the flavour and satisfaction is easy to appreciate as well.

There are obvious creamy and nutty qualities, but just the right high note of acidity from a squeeze of lemon waves hello when needed. Rosemary is woodsy and warm. Potatoes combine with the cauliflower to make a seriously creamy purée. This is a recipe I count on in the closing phase of Winter. There is much to anticipate—the seedlings and building projects of warmer days, but for now there are hardy vegetables and hot ovens to stay loyal to.

In the past couple weeks I’ve made not one, but two things that were total failures. The first was a batch of gluten free and vegan cinnamon buns that just flopped in every way. The second mishap was a flax granola that was, as I suspected it would be, much too flax-y for my liking. One day they will come to me (but not actually on that flax granola—wiping my hands of that). Tenured chefs get it wrong sometimes and the thought of this provides comfort, a laugh and the motivation to move on.

So I moved on to something I knew front to back and all through the dreamy middle. I used to cook at a little café and when I made it up, this roasted cauliflower soup was always received with a certain surprised approval. The rosemary fragrance and deep-warming nature of it brought people around I think. More simple blended soup goodness in the form of this kabocha squash one here, coconut green soup here, or this fennel walnut soup with turmeric here.

Hope you’re all having some cozy and easy days by the oven or wherever you like to be. I had a brief glimpse of sunbeams and chirping birds on an outing today, so I know that the world is at work on something wonderful for us all over again in the coming months. Be warm in the meantime!

2 photos: one is a sprig of rosemary on top of a wooden cutting board. The other is an overhead shot of a roasting tray with browned onions, cauliflower, and potatoes with a squeezed lemon half.
An overhead shot of a bowl of vegan roasted cauliflower soup, garnished with croutons and chopped parsley. The soup is beige. The bowl is on a beige napkin, which is on top of a wooden cutting board.

Vegan Roasted Cauliflower Soup with Potatoes, Rosemary & Lemon

Vegan roasted cauliflower soup with potatoes, lemon, and rosemaryis simple to make, super satisfying, and just so delicious.
4.83 from 28 votes
A slight 3/4 angle shot of vegan roasted cauliflower soup. The soup is beige and topped with croutons, chopped parsley, and balsamic reduction. It is in a white bowl on a beige napkin, on top of a black background.
Prep Time: 15 minutes
Cook Time: 1 hour
Total Time: 1 hour 15 minutes
Servings 4 -6

Ingredients

Soup

  • 1 large head of cauliflower
  • 1 lb yukon gold potatoes, scrubbed
  • 2 medium yellow onions, papery skin removed
  • 1-2 tablespoons fresh rosemary leaves
  • 2 tablespoons olive oil
  • sea salt and ground black pepper, to taste
  • 1 tablespoon fresh lemon juice
  • 5-6 cups vegetable stock

To Serve (optional)

  • more olive oil
  • croutons
  • toasted and chopped nuts
  • chopped leafy herbs
  • balsamic reduction
  • squeezes of lemon
  • more ground black pepper

Equipment

Notes

  • If you aren’t using homemade stock, most definitely use a no-salt-added variety. I advise on liberally salting the vegetables pre-roasting, so being in control of this factor throughout is ideal.
  • If you’re avoiding extra carbohydrates, you can simply leave the potatoes out of the recipe and double up the cauliflower. 

Instructions

  • Preheat the oven to 400°F.
  • Remove the core from the cauliflower and chop it into rough florets. Place the florets into a 9 x 13 glass baking dish.
  • Chop the potatoes into pieces about half the size of the cauliflower florets and toss them into the baking dish as well.
  • Chop the onions into rough 1-2 inch pieces and toss them into the dish. It doesn't matter if the onion layers stick to each other.
  • Sprinkle the rosemary leaves over the vegetables in the dish. Liberally salt the vegetables and season with pepper to taste. Add the oil and toss the vegetables until evenly coated with the oil, rosemary, and seasoning.
  • Roast vegetables for about an hour, flipping and tossing them here and there with a spatula/spoon to promote even browning. When done, remove from the oven and pour the lemon juice over the hot vegetables (I just drop the lemon half into the warm pan when I'm done so that it can release some oil too). Using your spatula, toss the vegetables with the lemon juice, scraping the browned bits off the bottom.
  • Once the vegetables are cool enough for you to handle, start blending them in batches with the vegetable stock. Purée until smooth and pour into a big soup pot. Continue blending in batches until you've used up everything. Heat the larg pot full of puréed soup over medium heat until it comes to a boil. Add more stock or water to thin the soup out if necessary and adjust seasoning to taste. Serve hot with optional garnishes.
20/02/2013 (Last Updated 06/01/2024)
Posted in: autumn, creamy, earthy, gluten free, grain-free, main course, nut free, quick, refined sugar-free, roasted, salty, soup, sour, spring, summer, vegan, winter

65 comments

Recipe Rating




  • Julie

    5 stars
    I’ve made and shared your recipe for years. It’s one of my all-time favorites. You used to include excellent advice about the lemon juice: This is one case where more isn’t necessarily better, and the amount you listed is just right. It brightens the flavor without making the soup taste too acidic.

  • Becca

    Do you roast and blend the onions? 

    • Laura

      Hi Becca,
      Yes, you do. Check out step 4 of the recipe! All of the vegetables are roasted and blended together.
      -L

  • Barb

    I find the name misleading. A pound of potatoes?? Looking for cauliflower soup, not potato soup. I’m sure it’s good, will keep looking for healthier version.

  • marie-eve crepault

    Hi!
    Love your recipes! I am trying to include more and more vegan dishes in our family life (my hubby is still not convinced) but your recipe are helping! I would appreciate to know when the recipe can be frozen. Or/and ow long they can keep.
    Thank you
    Marie

  • Cauliflower puree

    In your picture this soup looks great but the real taste is even better! Thanks!

  • Njemile

    Okay, I just made the soup and the puree of roasted cauliflower with hint of light coconut milk did the trick. I got a nice and creamy base for my soup!

    • Laura Wright

      That’s great Njemille! Sometimes if I’m trying to make a soup creamy without extra heavy fats and overly excessive carbs, I use cooked white beans pureed into the mix as well.
      -L

  • Njemile

    I am searching for vegan recipes which are light on the carbs! Trying to achieve the creamy soup texture without potatoes OR calorie-laden nut mixtures.

  • Gloria Huerta

    We made this tonight … and it tasted like mashed potatoes … so I decided to sauté two stalks of leeks in vegan butter until transluscent, add about half a cup of yeast flakes, add roasted sweet corn (which I had on hand in the freezer), then I added the potato/cauliflower mixture to it and watered it down some; adjusted the taste by adding garlic salt ….

  • Ruth

    love the recipe

  • Cindy

    Hi Laura,

    What kind of vegetable stock did you use? Mine was tomato based which made it a bright orange and entirely masked the taste of the vegetables. The vegetables, though, mmmm, amazing.

    • Laura Wright

      Hi Cindy,
      I almost always use a vegetable stock that has celery, carrots, onion (not red), leeks, thyme, parsley stems, peppercorns and sometimes parsnips if I have them. I usually make my own and it turns out pale yellow to golden almost always. When I specify vegetable broth/stock in my recipes, this is the kind I’m referring to. I never use cruciferous vegetables, leafy things or highly acidic vegetables (like tomatoes) for stocks as they change whatever soup I’m using them for too much. I’m guessing your vegetable stock had tomato pulp too? This would explain the colour change and weirdness in taste. Next time seek out a plainer one like I described and it will definitely turn out as pictured/taste better.
      -L

  • Senel Akarca

    Roasted some garlic with this and it’s amazing! Served it with some pumpkin seeds and sourdough. Angelic.

  • Lena

    Thanks for your help, Laura! Can’t wait to taste the soup on Thanksgiving. :)

  • Lena

    Looks amazing! How many people do you think this would serve? Also, as I am hoping to make this for Thanksgiving, do you think that it could be made ahead and hold up well in the fridge? Thanks for the great recipe!

    • Laura Wright

      Hi Lena, If I remember right, I think this makes roughly two litres of soup. So 7-8 smaller servings I guess? This recipe holds up wonderfully in the fridge–I find it actually tastes better if it gets a day or so to hang out. Also, if you need to double the recipe and are worried about leftovers, it freezes incredibly well. Hope this helps!
      -L

  • Michael Phelan

    Thanks very much for getting back to me, Laura. Made it tonight with the Japanese yam and it was lovely. a bit sweet for my taste so i’ll have to try a yukon gold the next time.

  • michael

    Hi Laura,
    Big fan of your recipes and your gorgeous blog, although this is my first post. It gives me a wonderful taste of my home and native land which I miss dearly since my move to the U.S. nearly 10 years ago. At any rate, any chance a sweet potato with light colored flesh (japanese yam) might sub for the yukon golds in this recipe? As much as I love potatoes, they just don’t love me back.

    • Laura Wright

      Hi Michael! Thanks for your kind note. I think a Japanese yam would work just fine here. It might not make for suuuuch a creamy/thick soup, but it’ll certainly get the job done. And the sweetness of it might be nice with the roasted onions/cauli.
      -L

  • Jooly

    Luscious. My only add was about 1/2 cup of white wine as my thinning agent. My particular cauliflower was about the size of George Clooney’s space helmet in Gravity, so I named this batch after the recipe’s predominant herb and called it Rosemary Clooney Soup.

  • sue

    is this soup freezeable?

    • Laura Wright

      Hi Sue, yes it’s highly freezeable!
      -L

  • BrandyBora2000

    This was such a great soup! I made fried shallots as a topping.

  • Michelle

    That looks yummy! I’ll put this on my recipe list. Thank you!

  • TheBigBeef

    Ive known alot of women that could not cook, this recipe is so simple even they could feel like a big winner!

  • Amelia

    Hey there, in the same cruciferous boat I bought a collie on a whim and wanted a soup from it, I found your site and we made this one tonight! Deeelish and Amazing! (I am satisfied but still go back for spoonfulls hehe)
    To up the vegan lovin’ protein I added a tin of organic canellini beans (white ones) and also some garlic cloves and thyme. Brilliant, well done :) xxx Amelia

  • Judith Heinemann

    I made this soup this evening and it is wonderfully delicious.
    Thank you so much for sharing the recipe. It will remain one of my favorite soups.
    Gratefully,
    Judith

  • Maria

    Just made this soup and it’s GREAT! I left out the rosemary (not a fan) and I used chicken stock (all I had!) but it came out GREAT! I also added some garlic cloves to the roasting. You’re right about the lemon part, using it sparingly!

  • hana

    these pictures are gorgeous. is it shot with film? and what kind of camera?

    • Laura Wright

      Hi Hana! Thank you for your comment. I do shoot with a digital camera (A Canon 5D Mark II), but I process the images with Visual Supply Co’s digital film manipulation software. Very cool thing to play around with if you shoot digital and have Lightroom or some such program on your computer. Here’s their site: http://vsco.co/
      -L

  • hungryandfrozen

    I admit I’m not the soupiest person – given the chance I’ll almost always choose something else on the menu. This sounds amazing though, and as the weather is getting colder I think I really will give it a try. Especially as it has so few ingredients and so little effort involved…also I hear you on the failing-at-recipes-blah feeling, so good when you get the confidence back though!

  • Julia

    WOW, this looks and sounds so delicious. Im having a real love affair with cauliflower at the moment – i cant get enough of it! I can’t wait to try it out myself.

  • Charul @ Tadka Masala

    Your pic made me drool, like literally! Yumm looking soup and so simple and easy to make. Roast and blend. I am sooo making it. :)

  • Elizabeth

    Ahh, I so love the roast and blend method. I was making my own cauliflower soup this week when the oven broke. So I blanched and sauteed instead. My recipe really went off the rails when I added WAY too much bacon, so that instead of cauliflower soup, I have bacon soup. Anyway, kitchen failures keep things real, and I guess we learn from them? Here’s hoping And here’s to your gorgeous, bacon-free, cauliflower soup!

  • la domestique

    This morning I baked Heidi Swanson’s rye soda bread and have been dreaming of a soup like this one to garnish with crunchy croutons when this loaf nears its end. This looks perfect. We got a good snow last night, and it does feel oh so wintry here. Stay warm!

  • Kathryne

    Ohh, I get so frustrated when my surely “brilliant” recipe concepts disappoint in execution. You’re much more of a chef than I, so it’s heartening to hear it happens to the best. I wasn’t keen on cauliflower until I tried it roasted last year, and I wasn’t sure about cauliflower soup until my friend served it at girls’ night. Delicious! Your version sounds amazing, I’m a big fan of anything involving lemon and rosemary.

  • Sara {Home is Where the Cookies Are}

    Yum! I absolutely LOVE roasted Cauliflower. I was just dreaming about something along these lines yesterday – what perfect timing for me!!

  • Shira

    Simply beautiful Laura! The best way to win is with delicious soup – I’ve been enjoying roasted cauliflower in so many ways recently and happen to have 2 in the fridge that have begging me to make soup with them :) YUM!

  • Shoba Shrinivasan

    Thats such a hearty warm filling soup.. Looks like its an easy fix as you throw everything including the rosemary in to the oven and then puree it…me Likes!!! Lovely clicks by the way<<< Did you use a macro lens? Great shots.

    Shobha

  • Eileen

    Hooray for creamy cauliflower soup! That rosemary looks so thick and green too. :)

  • Katrina @ Warm Vanilla Sugar

    This looks so fabulous!

  • Alicia@ eco friendly homemaking

    Oh this soup looks amazing!!

  • Laura (Blogging Over Thyme)

    Beautiful! And sounds so delicious, too. Cauliflower is one of my favorite vegetables to roast. And especially love all the exciting toppings and garnishes :)

  • Joanne

    I love that you roasted the veggies for the soup…that must give it such a fabulous depth of flavor!

  • Michelle

    This looks so warming and filling. With the terrible cold days we’ve been having in Boston I will definitely add this to the ever rotating list of soup recipes I’ve been living off of.

  • Suzanne @RollWithIt

    This soup looks perfect for a cold day. I love the idea of rosemary – great idea!

    I had a week of baking disasters in my kitchen too – the gluten-free cake mix is killing me right now! Cannot get the right consistency. So instead I made come glazed carrots – and all was well in the world again.

  • Heather

    I’m glad you finally settled on this soup, because it looks incredible.

  • Leslie

    I am so glad this calls for rosemary, it is exactly the sort of ingredient that can entice me to try a cauliflower soup. I can’t wait to make this for the weekend!

    And Then The Doorbell Rang

  • Kate

    Every failure teaches us a little more about us, and about what we work with, eat, share and talk about to others. I never look at them as a bad thing.

    I love the photos of that soup, too. I love the textures against the creamy background. Whenever I’m faced with a smoothly pureed soup, I long for something in it to sink my teeth in to, to feel like I’m actually eating something as opposed to tasting and swallowing. My teeth like the workout, I think. But top a smooth soup with big chunks of extras, and I will dive in, spoon first, and will likely come up smiling. What a beautiful dish.

  • Michelle

    Gorgeous, lady. This (plus my new tea addiction) is exactly the kind of thing I need to get me through late February/early March. I feel like that is the time of Canadian winter you start questioning why you choose to live in this goddamn country, am I right? The rest of the time, it’s pretty great.

  • Kierstan

    I am all about roasted + pureed soups like this one. I am going to have to add it in to my rotation.

  • thelittleloaf

    I love that photo with the cauliflower and lemon – beautiful! As for mistakes, everyone makes them – I’ve had so many kitchen disasters but the positives always win through :-)

  • Natasha

    I had a similar experience a few weeks ago. I think I made three different things in a week, all failures. I decided it wasn’t meant to be and took a break from trying to make it work. I guess I just needed to reset. I feel like I learn so much from the failures though, so I guess it’s ok to have them. And returning to something tried and true probably helps. This soup looks wonderful–warming and comforting.

  • Caitlin

    what a delicious, creamy soup! i, for one, am a huge lover of “peasant” type meals. and when roasted cauliflower is involved…i’m jumping all over it.

  • Kathryn

    Oh I know that feeling all too well – when I’m feeling positive, I like to think that each of those kitchen failures is making me a better cook. In the darker moments, I feel like never turning the oven on again. I always find a need a killer recipe in that situation and this recipe really looks like one.