Soup is really about layering flavor, not just tossing things into a pot with water and calling it done. Keto roasted cauliflower soup starts with roasting the cauliflower first, and that single step changes the whole flavor of the finished bowl.
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The result is thick, creamy, and genuinely nutty tasting, closer to what you would get at a restaurant than a quick weeknight soup. It also happens to be very easy to make.
Use fresh cauliflower, not frozen. Frozen cauliflower holds too much water to properly roast and brown.
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Chef Jenn’s Take on Roasted Cauliflower Soup
A lot of soup recipes skip straight to dumping vegetables and broth into a pot. Real flavor comes from layering things in order instead, starting with a good stock or broth base, homemade if you have it.
Browned vegetables matter more than raw ones. Roasting or sauteeing caramelizes them first, and that caramelization adds a depth raw vegetables simmered in broth never quite reach. Aromatics come next, onion or shallot, garlic, and any herbs. Fat goes in last, and it gives a cream soup like this one its richness.
Use fresh cauliflower here, not frozen. Frozen cauliflower holds too much water to properly roast and brown, so it never develops the nutty flavor the roasting step is meant to build. Shallots are my pick over onion, milder and a bit sweeter, though a small amount of yellow onion works in a pinch. Skip red onion specifically, it turns the whole soup an unappealing color.
One reader who doesn’t normally like cauliflower said the roasting step won her over completely. A pinch of dried thyme is a nice addition, and green onion with sharp cheddar makes a good finishing garnish.
What You’ll Love About Roasted Cauliflower Soup
- Freezes well, so a batch stretches across more than one meal.
- Thick, creamy, and genuinely nutty, closer to a restaurant soup than a quick weeknight one.
- A short ingredient list with real, layered flavor built into every step.
Ingredients
- Cauliflower – Fresh, not frozen. Cut into chunks a bit bigger than bite-sized.
- Shallots – Milder and slightly sweeter than onion. A small amount of yellow onion works in a pinch, but skip red onion, it discolors the soup.
- Garlic – Fresh cloves.
- Chicken broth – Homemade or store-bought, low sodium. Vegetable broth works too.
- Heavy whipping cream – Full fat.
- Cooking oil – Avocado oil works well here.
How to Make Roasted Cauliflower Soup
Scroll down for the full recipe card with exact measurements and printable instructions.
Remove the stem from the cauliflower and cut it into chunks. Combine the oil with salt and pepper, and toss the cauliflower with the seasoned oil.
Arrange the seasoned cauliflower, peeled and cut shallot, and peeled garlic on a sheet pan. Roast in a preheated 425°F oven for 10 to 15 minutes, until golden brown.
In a large pot, bring the chicken broth to a simmer. Add the roasted cauliflower, shallot, and garlic, along with any pan juices. Simmer for about 10 minutes, until the cauliflower is very soft.
Remove from the heat and puree with a blender or immersion blender until smooth. Add the cream and season with more salt and pepper as needed, adjusting thickness with extra cream or broth.
Serve topped with shredded sharp cheddar and chopped green onions.
Make It A Meal
Pair this with Broccoli Cheese Soup or Cream of Roasted Broccoli Soup for a rotation of creamy keto soups. For something heartier, Beef Pot Roast Soup rounds out a soup-focused week nicely.
Storage
Chill fully overnight in the fridge, then fill freezer-friendly containers and freeze for up to 3 months. Thaw overnight in the fridge, then warm gently on the stovetop or in the microwave. Avoid boiling it hard when reheating.
Frequently Asked Questions
This recipe runs about 4 net carbs per 1 cup serving. The number in the recipe card below will recalculate once this post is republished, so use it as an estimate until then.
Top it with crispy chopped bacon, or add a dollop of sour cream for extra richness.
Yes, cauliflower is naturally low in carbs and works well in a variety of keto recipes, this soup included.
Use about 1/4 of a yellow onion instead. Avoid red onion specifically, since it turns the soup an unappealing color.
Add Preferred SourceCreamy Roasted Cauliflower Soup
Ingredients
- 1 head of cauliflower
- 1/4 cup oil
- 1/2 teaspoon salt
- 1/4 teaspoon pepper
- 1 shallot
- 3 cloves of garlic
- 3 cups low-sodium chicken stock
- 1 cup heavy whipping cream
Instructions
- Remove the stem from the cauliflower and cut it into chunks.
- Combine the oil with the salt and pepper. Toss the cauliflower with the seasoned oil.
- Put the seasoned cauliflower, peeled and cut shallot, and peeled garlic onto a sheet pan.
- Roast the garlic in a preheated 425-F oven for 10-15 minutes or until it is golden brown.
- In a large pot, simmer the chicken broth. Add the roasted cauliflower, shallot, and garlic, plus any pan juices, to the pot. Bring to a simmer and cook for about 10 minutes or until the cauliflower stems are very soft.
- Remove from the heat and puree in a blender or with an immersion blender.
- Add the cream and season with more salt and pepper if needed. Add extra cream or chicken broth to reach your desired thickness.
- Serve topped with shredded sharp cheddar and chopped green onions. Enjoy!
Notes
Recipe Card Tips
- Use fresh cauliflower, never frozen. Frozen cauliflower holds too much water to brown properly.
- Skip red onion if you don’t have shallots. It turns the finished soup an unappealing color.
- Layer the flavor in order, broth first, then browned vegetables, then aromatics, then the cream at the end.
Nutrition
A Note on Nutritional Information
Nutritional information for this recipe is provided as a courtesy and is calculated based on available online ingredient information. It is only an approximate value. The accuracy of the nutritional information for any recipe on this site cannot be guaranteed. Erythritol carbs (sugar substitutes) are not included in the carbohydrate counts as they have been shown not to impact blood sugar, and they have zero calories and zero carbs. Net carbs are the total carbs minus fiber.
Love soups? Be sure to check out even more keto soups and chowders, and you can pair any one of these amazing keto soup recipes with a keto sandwich or a serving of leftover keto casserole.
Want more easy keto recipes?
- Crack Cauliflower
- Sausage & Sauerkraut in the Instant Pot
- Spaghetti Squash with Parm in the air fryer
- A meaty breakfast hash
- This beefy vegetable soup
I love the simple ingredients in this recipe. It tastes fresh and delicious, and has the perfect creamy texture!
It is one of my faves, and I like that I can thin it to the perfect consistency.
Winter is the perfect time for trying new soup recipes. Putting this on my menu for next week!
I’m a winter soup fan, too! Hope you enjoy it!
I love cauliflower soup, and roasting the cauliflower in advance makes it so much more flavorful. Thanks so much for sharing!
This soup was so delicious! I love roasted cauliflower and this is perfect.
CAn’t wait to try this. I love Cauliflower and I love that this is a simple recipe with a short ingredient list! Less work for me.
This comes out SO creamy and I love that it’s an easy way to sneak in extra veggies that the kiddos ENJOY
I had extra cauliflower coming out of the garden and decided to try your Keto soup recipe. Your soup recipe was so easy to make and tasted amazing! I will be making this recipe again and again!!
We really loved this soup! It had the perfect creamy consistency, and the touch of garlic gave it such a nice flavor. Super simple to prepare too!
You weren’t kidding when you said thick and creamy! Sooo good! We’ll be making this again – everyone loved it!
Love this soup! I don’t love cauliflower normally, but roasting it really brings out the flavor so that I truly enjoy eating this soup. Topping it with green onions and cheddar makes it that much better.