A dairy-free, roasted cauliflower soup that is full of warm spicy flavors. This bold umami recipe is the antidote to a cold night or a much needed pantry clean-out.

black bowl of vegan cauliflower soup with a white spoon and a cut lemon and bowls of crushed red pepper and flat leaf parsley on a marble hexagon tile background

How are you with leftovers? I mean really using things that are potentially on their last legs? Vegan cauliflower soup came from doing just that. This creamy (non-dairy), roasted cauliflower soup will win over anyone in your house who isn’t a fan of leftovers.

Like my leftover averse husband.  

I know. He’s married to a food blogger. 

He’ll eat leftover steak chili or homemade meatballs for like two weeks but isn’t a fan of eating food out of leftover containers. We all have our quirks.

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What to do with leftovers

white bowl of roasted cauliflower with meausuring cup of broth and a lemon,onion, umami powder and crushed red pepper on a marble hexagon tile background

However, he did give this roasted cauliflower soup a big thumbs up. Maybe it’s because he didn’t know (until now) that this recipe was created from a bunch of leftover roasted cauliflower. 

And that’s what’s beautiful about knowing basic cooking techniques, like making this soup. You have the power to transform something “formerly new” into something newer. I once read that one of the best attitude adjustments cooks can make regarding leftovers is to start thinking about them as ingredients.

So —let’s get to some attitude adjusting.

One unique cauliflower soup

Trader Joe's Umami Powder, a cut lemon half and bowl of roasted cauliflower on a white marble hexagon tile background

Why is this cauliflower soup different? One word.

UMAMI.

Umami is called the fifth taste and it naturally occurs in foods like red meat, tomatoes, Parmesan cheese, mushrooms and more. And our pals at Trader Joe’s have made it extra easy to add umami to dishes (especially if we know someone who might not be eating one or more of those umami-rich ingredients) with their umami mushroom powder and seasoning blend. 

Trader Joe’s mushroom powder doesn’t taste like mushrooms but gives you all the mouthwatering umami of mushrooms.

How to make creamy cauliflower soup

soup pot of roasted cauliflower and broth with a wooden spoon on a gray napkin and a lemon and zester on a marble hexagon tile background

You can be eating this soup in under 20 minutes if you have leftover roasted cauliflower. If not, add another 20 minutes to that estimate.

  • Roast your cauliflower until it’s golden brown
  • Saute a combo of vegetables. Many soup bases start with a trio like chopped onion, celery and carrots. In Italian cooking, this is called a soffritto. We are using onion, garlic and cauliflower. You could add carrots for a little sweetness, especially if you have some you need to use up.
  • Season the vegetables with a blend of spices and herbs, gently warming them to allow them to bloom and release their flavor.
  • Simmer the soup base to marry everything together.
  • Blend and bring all the ingredients together to make a smooth texture that is balanced in flavor and no ingredient standing out too much or too little. 

Herbs and spices

soup pot of roasted cauliflower and broth with a wooden spoon on a gray napkin and a lemon and zester on a marble hexagon tile background

Trust me. This is no bland cauliflower soup. Between the umami powder and the lemon juice and zest, it makes for a hearty, comforting bowl of soup. And spicing things up with a little cayenne or hot chili powder is more than acceptable.

If your pantry doesn’t have one of the spices in the recipe, you definitely can go rogue. Here’s a starting list of spices and herbs that play nice in a vegan cauliflower soup. 

  • Chili powder
  • Coriander
  • Cumin
  • Dill
  • Oregano
  • Thyme
  • Turmeric
  • Basil
  • Chervil
  • Cilantro
  • Fennel
  • Fresh Parsley
  • Mint

Safety Tips for Pureeing Hot Soups or Sauces

blender of vegan cauliflower soup ingredients with a towel over the lid.
blender of vegan cauliflower soup ingredients with a towel over the lid.

Danger, Will Robinson. When it comes to blending hot mixtures, there’s a few things you need to know:

PLEASE – DO NOT PUT THE CENTER BLENDER CAP ON THE BLENDER’S LID. OTHERWISE, THE BLENDER WILL EXPLODE AND YOU WILL HAVE CAULIFLOWER SOUP EVERYWHERE AND POSSIBLY BURN YOURSELF.

Instead:

  1. Pour the hot mixture into the blender.
  2. Place the lid on the blender.
  3. Remove the center cap and set aside.
  4. Fold a clean and dry dish towel and hold it over the hole’s opening, covering it completely. This allows steam to escape
  5. Turn the blender on at the lowest speed, keeping the towel over the opening, and slowly ramp up the speed until the soup reaches the desired texture.
  6. Turn off the blender, taste for seasoning and texture. Adjust as needed. 

How to thicken soup without flour or milk

soup pot of roasted cauliflower, seasoning and broth with a wooden spoon on a gray napkin and a marble hexagon tile background

The best thing about this roasted cauliflower soup is that you don’t have to thicken it using anything other than the cauliflower and a blender. Cauliflower is rich in pectin which is a natural thickener. Think apples in applesauce or what helps jam become jam.

Technique tip: you can use other pectin rich veggies like potatoes or carrots to thicken soup in the same way.

One more win for the leftovers!

Tips

black bowl of vegan cauliflower soup with a white spoon and a cut lemon and bowls of crushed red pepper and flat leaf parsley on a marble hexagon tile background

For a crowd: Serve in shot glasses as an appetizer at a party sprinkled with chili powder and lemon zest.

For a few: Make as is and freeze the rest. See the recipe for freezing tips.

Made this recipe?

I’d love it if you’d share your review and leave a star rating and comment!


black bowl of vegan cauliflower soup with a white spoon and a cut lemon and bowls of crushed red pepper and flat leaf parsley on a marble hexagon tile background
5 from 1 vote

Roasted Cauliflower Soup with Lemon

A clean out the pantry soup made with roasted cauliflower, bright lemon and a hit of umami.
Prep Time:5 minutes
Cook Time:15 minutes
Cauiflower roasting:20 minutes
Total Time:40 minutes
Servings 6

Ingredients
 

  • 1 head cauliflower, trimmed and cut into medium-sized florets
  • 1 T oil, I use olive or avocado
  • ½ onion diced, small
  • 2 cloves garlic, chopped – or 2 tsp bottled garlic
  • 1 tsp umami mushroom powder, Trader Joe's
  • 1/4-1/2 tsp crushed red pepper
  • 1 tsp salt
  • ½ tsp black pepper
  • 3 cups vegetable broth, can substitute chicken or mushroom broth
  • ½ lemon, zested first, then juiced to 2 T

Instructions

  • Preheat oven to 375°
  • Add cauliflower to a sheet pan and roast in the oven for 20 minutes until browned.
  • Remove from the oven and set aside.
  • Meanwhile, heat oil in a 4 qt soup or saucepan and saute onion for 5 minutes until golden.
  • Add garlic the last minute of cooking the onions, stirring the whole time. Season lightly with salt and pepper. p.s. don't burn or over-brown the garlic.
  • To the soup pan, add the roasted cauliflower, umami powder and crushed red pepper along with salt and pepper. Stir to incorporate for about 1 minute.
  • Add chicken broth, lemon zest and the 2 T of lemon juice.
  • Simmer over low heat for 10 minutes or so.
  • Remove from heat and pour the contents of the pan into a blender.
  • Put the lid on the blender and REMOVE MIDDLE INSERT OF THE LID leaving the hole open.
  • Place a folded dish towel over the blender hole opening to allow steam to escape.
  • Turn the blender on low and slowly ramp up to medium-high speed stopping the blender as needed to scrape the sides or push down the ingredients.
  • Blend for about 1-2 minutes until you can a super-smooth texture. Of course, if you like bits of cauliflower, stop the blender sooner.
  • Taste and correct for seasoning and/or texture by adding additional broth, if needed.
  • Pour into a serving tureen or bowls.

Notes

  • You can forego using roasted cauliflower if you want to save some time and then cook the cauliflower in the broth until soft which should take about 15 minutes.
  • Thin the soup with additional broth, if needed.
FREEZER TIPS
Can be frozen for up to three months. Reheat in a saucepan in the stove adding more broth or seasoning if needed.
**BLENDER SAFETY WARNING**
PLEASE – DO NOT PUT THE CENTER BLENDER CAP ON THE LID OR THE BLENDER WILL EXPLODE. YOU WILL HAVE CAULIFLOWER SOUP EVERYWHERE AND POSSIBLY BURN YOURSELF.
Course: Lunch, Main Course, Soup
Cuisine: Mediterranean
Author: Lori Murphy
Did you make this recipe? Tag @josieandnina or tag #josieandnina!
5 from 1 vote (1 rating without comment)

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2 Comments

  1. Delish! If I didn’t make it myself I’d swear it had cream and cheese in it. Thanks for a really tasty vegan soup, Lori. Love the TJ spice too. Using umami spice In everything now.

    1. Thanks so much Mary! That umami spice is AMAZING and brings out the flavors in anything especially vegetables so well!