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Vegan Spicy Vegetable Soup

This spicy vegetable soup gets its heat from Tunisian harissa paste and features cauliflower, sweet potato & spinach in a hearty vegan munch!

Portrait image of a steaming hot spicy vegetable soup with sweet potato, cauliflower and in a harissa broth in a ladle

Easy Spicy Vegan Soup

My site is positively dripping with soup recipes and more than its fair share of spicy soup recipes. Many of them are vegetarian or vegan.

But there is always room for more and this hot and spicy vegetable soup recipe showcases cauliflower and sweet potato.

I love cauliflower, it has appeared here in dishes as diverse as my cream of cauliflower soup through to my roasted cauliflower steak.

It sits alongside soft and earth sweet potato. An ingredient that I think is great with North African flavours as my sweet potato tagine demonstrates.

Our simple “broth” is nothing more than tomato passata and vegetable stock. This is seasoned by the classic herb mix Zaatar.

Finally, our spicy kick comes from Tunisian harissa paste and a bit more chilli!

Portrait image of a spicy vegetable soup with sweet potato, cauliflower and in a harissa broth

Frequently Asked Questions

What is harissa paste?

Harissa paste is a Moroccan and Tunisian spiced pepper paste and I the stuff a lot!

Harissa has a deep almost smoky complex flavour and features many types of pepper, cumin, caraway, and coriander among a host of other flavours.

It is great as a base flavour for soups or stews as we use it here or in my spicy vegetable tagine.

It is also great as a glaze for meat or fish. I use it with dried mint for my harissa pork chops and you simply must try my harissa garlic prawns!

What is Zaatar?

Zaatar, is a spice blend that pops up here in dishes like my halloumi burger and my lamb tagine.

It is a sprawling mix of sesame seeds, sumac, savory, thyme, oregano and lots of other goodies.

It often contains salt too so be careful when seasoning this recipe, you may not need to add any salt at all!

Can I make this in advance?

Yes, this dish will store in the fridge for 4-5 days but you will need to add more stock to warm it through.

As a bonus, the flavours really develop when this spicy soup is made in advance. I have tried freezing it but am not keen on the texture when it reheats.

Portrait close up image of a spicy vegetable soup with sweet potato, cauliflower and spinach in a harissa broth

Serving Suggestions

A bowl of soup is always great with bread and this one is no different.

If you were feeling adventurous you could give this Moroccan Khobz recipe a try.

Although I recently served this with a no-knead ciabatta bread from my friend Rosemary and it was the perfect accompaniment.

Other than that I just sprinkle on loads of fresh coriander or parsley and call grubs up!

If you like your soups a little “thicker” you can blend part of it mix it all together.

Landscape close up image of a spicy vegetable soup with sweet potato, cauliflower and in a harissa broth

Equipment Used

I only name-check brands of equipment if I think that they make a material difference to a recipe. But if you have any questions feel free to ask them in the comments section below the recipe.

  • Stovetop.
  • 20cm or 8″ saucepan.
  • Chopping board.
  • Kitchen knife.
  • Vegetable peeler.
  • Weighing scales and or measuring jug, cups and spoons.
  • Stirring and serving spoons.
Square image of a spicy vegetable soup with sweet potato, cauliflower and in a harissa broth
Yield: 2 Servings

Spicy Vegetable Soup Recipe

Prep Time: 5 minutes
Cook Time: 45 minutes
Total Time: 50 minutes

A hearty and warming, easy spicy vegetable soup powered by the glory of harissa paste and loaded with sweet potato, cauliflower and spinach.


  • 200g (1½ Cups) Sweet Potato
  • 250g (2 Cups) Cauliflower
  • 75g (3-4 Cups) Baby Spinach
  • 75g (½ Cup) Onion
  • 75g (½ Cup) Carrot
  • 35g (¼ Cup) Celery
  • 1 Medium hot Chilli Pepper
  • 2 Garlic Cloves
  • 1 Tbsp Cooking Oil
  • 2 Tbsp Harissa Paste
  • 1 Tbsp Zaatar
  • 250 ml (1 Cup) Vegetable Stock
  • 250 ml (1 Cup) Tomato Passata
  • Salt to Taste


  1. Cut the onion, carrot, and celery into a 3-4mm (⅛-¼") dice.
  2. Heat a 20cm or 8" saucepan over a low to medium heat and add the oil.
  3. Add the diced carrot, onion, and celery and soften for 10 minutes.
  4. Dice the garlic as finely as you can.
  5. Slice the chilli pepper into thin rounds.
  6. Peel the sweet potato and cut into a 1cm (½") dice.
  7. Add the sliced chilli, garlic, and sweet potato along with the harissa paste and zaatar.
  8. Stir and combine for 2-3 minutes.
  9. Pour in the vegetable stock and passata, stir, taste and add as much salt as required.
  10. Add a lid and simmer for 15 minutes.
  11. Cut the cauliflower into 1-2cm (½-¾) florets.
  12. Add the cauliflower to the pan, return the lid, and cook for 10 minutes.
  13. Add the spinach and stir until wilted and then serve.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 589Total Fat: 29gSaturated Fat: 7gTrans Fat: 0gUnsaturated Fat: 17gCholesterol: 50mgSodium: 1783mgCarbohydrates: 60gFiber: 14gSugar: 18gProtein: 27g

Calorific details are provided by a third-party application and are to be used as indicative figures only.

Did you make this recipe?

If you made this recipe, I'd love to see what you did and what I can do better, share a picture with me on Instagram and tag me @krumplibrian and tell me how it went!


Sunday 6th of June 2021

Step 3: cucumber? Is this supposed to celery?

Brian Jones

Tuesday 8th of June 2021

Yes, thanks for the heads up, I've changed that :)

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