Low Carb Cauliflower Soup with Roasted Garlic

5 from 1 vote

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Roasted cauliflower soup with roasted garlic is one of my favorite soups. With just 9 grams of net carbs, this healthy cauliflower soup is perfect for those on a keto diet and others like myself who love good soup recipes.

Read on, and I’ll show a great way to take a head of cauliflower and turn it into a delicious bowl of creamy soup!

A spoonful of soup coming out of a bowl.
Creamy cauliflower soup is a perfect comfort food loaded with rich flavors.

About this recipe

This healthy soup is perfect for anyone on a low-carb diet. Cauliflower florets and other simple ingredients like garlic cloves and fresh parsley are combined in a broth base and half and half.

The result is a velvety soup the whole family can enjoy on those chilly nights during soup season.

What’s in it

(Full recipe in the recipe card below.)

Our creamy roasted cauliflower soup uses a classic mirepoix of carrots, onions, and celery. But after that, this low-carb soup is taken to the next level with roasted garlic and Parmesan cheese.

The half-and-half combines with the cheese to make a 5-star rating bowl of soup with a warm, creamy texture.

A bunch of ingredients in a big red Dutch oven.
The cauliflower and garlic are the stars of this low carb soup, but the rest of the ingredients are also pretty standard.

Cauliflower – You’ll need one large head of cauliflower for this easy soup recipe. If you’re wondering, here is an excellent post on the best way to cut a cauliflower.

If you’re shopping for cauliflower, pick out a head that is firm and dense. You’ll want it to feel heavy for its size.

Expert Cooking Tip – To save a little time and mess, you can buy pre-cut cauliflower florets in the grocery store. You’ll need about 5 cups of florets for this cauliflower soup recipe.

Garlic – We roast a head of garlic with the cauliflower to give this cauliflower soup a nice flavor pump. If you are like me and love garlic, you can add an extra head to this.

Half & Half – If you want to bump up the fat content and turn this into a rock star keto cauliflower soup recipe, use heavy cream as a substitution.

Broth – We use vegetable broth for this, but you can use chicken stock or even chicken bone broth for added flavor. This would make it even more of a keto soup recipe. Substitute the veggie broth for equal cups chicken broth.

Parmesan cheese – You can use Pecornio Romano cheese for a similar flavor profile.

How to make roasted cauliflower soup

Gather all of your ingredients and a few other kitchen items:

  • An immersion blender
  • A baking sheet
  • Parchment paper and aluminum foil
  • You’ll need a large pot like a Dutch oven to finish the whole thing.
A sheet pan of roasted cauliflower and garlic.
This roasted cauliflower soup starts with some yummy roasted vegetables from the oven.

Start by roasting the cauliflower florets and the garlic on a baking sheet lined with parchment paper. Do this in a preheated oven at 425°. These are ready to come out in 20 to 25 minutes.

For the garlic, slice the top off of a head of garlic, and add a drizzle of olive oil. You’ll want to encase the sides of the garlic in aluminum foil, as we show you here.

Expert Cooking Tip: Before roasting, you can use a mixing bowl to toss the florets in olive oil, salt, and pepper. This makes them a little browner and crispier for added flavor.

A pot of vegetables and a wodden spoon.

Use a large soup pot and saute the carrots, onion, and celery in some olive oil over medium heat. You’ll want the veggies to be soft but not mushy. The onions should be translucent (shiny and soft.) This will take about 7 to 10 minutes.

A big pot of vegetables in broth.

Add the florets to the pot, along with the broth. Squeeze the roasted garlic into the pot and toss in the fresh thyme.

You’ll bring this to a boil and then reduce it to a simmer for about 15 minutes.

Finally, you’ll use an immersion blender to puree the this roasted cauliflower soup. You can also use a food processor or regular blender if you don’t have a stick blender.

Now, add the cheese, the half and half, and the rest of the seasoning. Let it all simmer for a few minutes, and grab a saddle and some soup bowls. This is going to be good!

A big pot of soup with chopped fresh parsley.
Make this roasted cauliflower soup pretty by garnishing with some

Substitutions and variations

  • Use some green onions or even leeks for a flavor twist, in addition to the onions in the mirepoix. Reduce the amount of onion by about half if you make these substitutions.
  • You can use some shredded sharp cheddar cheese instead of the Parmesan and still make it a keto cauliflower cheese soup.
  • Add four oz. of cream cheese to the pot for a mellow touch.
  • A dash of chili powder or garlic powder will give this an extra kick.
  • Sprinkle with bacon bits made from crispy bacon at the end for added flavor and texture.
  • Add a dollop of sour cream when you’re ready to serve this.
  • To keep this non-dairy, you can use coconut cream instead of half and half.

What to serve with this

Dipping a big slice of bread into a bowl of soup.

Call me biased, but I think our homemade crusty bread is the best thing in the world to go with this roasted cauliflower soup recipe. Try this mandarin orange salad if you’re looking for something green and delicious. It’s the best ever!

Frequently asked questions

How do I store the leftovers?

Put the leftovers in an air-tight container and refrigerate for up to 5 days. To reheat it, use a saucepan over low heat. You can also pop it in the microwave for about 2 minutes on 50% power or use your reheat setting.

Can I freeze this?

This roasted cauliflower soup freezes beautifully, making it ideal for meal planning or eating something delicious at work.

Be sure to allow it to cool completely first. Then, dole out individual portions into a zip-lock bag, carefully removing all the air before sealing. Lay the bags on a cookie sheet and place them in the freezer. This will make them freeze flat and easier to store!

This soup stays good for up to 3 months in the freezer. Let it thaw in the fridge overnight before reheating.

How do I make this vegan?

Cauliflower soup is easy to make vegan! Use coconut oil instead of half and half and vegetable broth as a base.

More easy soups

More cauliflower recipes

Want to try more cauliflower recipes? Cauliflower Gratin is one of my favorite Thanksgiving side dishes. Thanks to the added horseradish, it has great flavor and an extra kick! Other recipes with cauliflower that you should try include our Cauliflower Latkes and this delicious Cauliflower Pork Fried Rice! For a little Indian spice in your life, try this cauliflower curry. It’s out of this world-delicious!

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Low Carb Roasted Cauliflower Soup with Garlic

5 from 1 vote
This healthy roasted cauliflower soup recipe is one of my favorites soups. Low in carbs, you can play with the flavor profile and it's so easy to make! What makes it even better, you can store the leftovers in your fridge or freezer. This makes meal planning and taking something warm and yummy to work with you a snap!
Prep: 10 minutes
Cook: 40 minutes
Total: 50 minutes
Yield: 8 people



  • 1 cauliflower , large head
  • 2 1/2 tbsp olive oil, divided
  • 1 head garlic
  • 1 cup onion, chopped
  • 2 carrots, large, chopped
  • 3 celery stalks, chopped
  • 4 cups vegetable broth
  • 1 tbsp fresh thyme, or 1 tsp. dried thyme
  • 3/4 cups half and half
  • 1/2 cup Romano cheese, or Parmesan cheese
  • 1 tsp. oregano, dried
  • 1 tsp. turmeric, ground
  • 1 tsp. salt, salt to taste
  • black pepper, ground, to taste
  • 1 tbsp parsley, fresh, chopped, for garnish


  • Roast the cauliflower and garlic: Preheat oven to 425°F. Line a baking sheet with parchment paper for easier clean-up. Cut up cauliflower into florets and spread out on a baking sheet. Drizzle 1 tablespoon olive oil over cauliflower and sprinkle with salt and pepper to taste. Slice off the top of a garlic head and wrap head in foil, drizzling a teaspoon or so of olive oil over the top of garlic. Place it on the baking sheet with cauliflower. Roast for 20 – 25 minutes, or until browning on the edges of the florets.
  • Make the Soup base: heat 1 tablespoon of olive oil in large dutch oven or stock pot over medium-high heat. Add chopped onion, carrots, and celery. Saute until soft and onion is translucent.
  • When cauliflower is done roasting, remove sheet from oven. To the pot, add the broth, and roasted cauliflower. Squeeze the cloves from the garlic head and add them to the pot. Add the thyme. Bring to boil, then reduce heat to medium-low. Simmer for 10 to 15 minutes.
  • Turn off burner. Use a stick blender or food processor to puree the soup. Stir in the half-and-half and the romano cheese. Add oregano, turmeric, and 1 teaspoon of salt. Add pepper to taste. Turn heat to medium and allow to simmer for 3 minutes more.


  • If you want to make this roasted cauliflower soup a bit thicker, you can add a cubed potato to the ingredients. For added flavor, roast the potato with the cauliflower and garlic!
  • Take this soup to the next level and add the zest of a lemon to the pot.


Calories: 143kcal, Carbohydrates: 12g, Protein: 5g, Fat: 9g, Saturated Fat: 3g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 4g, Cholesterol: 15mg, Sodium: 839mg, Potassium: 412mg, Fiber: 3g, Sugar: 4g, Vitamin A: 3066IU, Vitamin C: 41mg, Calcium: 143mg, Iron: 1mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Course: Soup
Cuisine: American
Tried this recipe?Mention @plattertalk or tag #plattertalk!

Meet the Platter Talk Guys

Dan & Scott split their time between Wisconsin and Southwest Florida and are dads to six boys. Good food runs through their veins, and they love showing others how to cook easy recipes.

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