Cheesy Broccoli Cauliflower Soup is a low-carb soup that’s loaded with flavor, and now it can be made in the Instant Pot or on the stove. And for the new Instant Pot version we also switched to using frozen cauliflower rice, which made the soup so quick and easy to make!

PIN Cheesy Broccoli and Cauliflower Soup to make it later!

Cheesy Broccoli and Cauliflower Soup shown in two serving bowls

Today I’m updating this long-time favorite recipe for Cheesy Broccoli Cauliflower Soup so it now has an Instant Pot version! And when you look at the photo can you tell I’m not kidding about the cheesy part of this recipe title?

I’m someone who really likes my cheese, but if you’re not quite as much of a cheese fan I promise the broccoli and cauliflower soup will be just as delicious with a more moderate amount of cheese.

And whether you try the new Instant Pot version or just make broccoli cauliflower soup on the stove, you’ll love the amazing flavor that results in a soup where broccoli is combined with melted cheese! My version also adds some cauliflower rice, partly to thicken the soup and partly because cauliflower is also something that tastes amazing with cheese! And if you use vegetable stock, this tasty soup can be vegetarian.

I’m giving you the ingredients for the new Instant Pot recipe, and of course I did make a few improvements when I updated the recipe. But if anyone was a fan of the original recipe or wants to compare, you can see that here.

What ingredients do you need?

(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)

  • Olive Oil (affiliate link)
  • onion
  • Minced Garlic (affiliate link)
  • Dried Thyme (affiliate link) or use Ground Thyme (affiliate link) if you have it
  • Spike Seasoning (affiliate link)
  • salt (more or less to taste)
  • chopped broccoli, including stems
  • frozen cauliflower rice (or chopped cauliflower, whichever you prefer)
  • canned chicken broth (affiliate link) or canned vegetable broth (affiliate link)
  • heavy cream, half and half, or milk
  • grated sharp yellow cheddar cheese
  • grated sharp white cheddar cheese
  • cornstarch (we used a very small amount which added 1 carb per serving; it’s definitely optional)
  • salt and fresh-ground black pepper to taste

Do you need two types of cheese for this Broccoli Cauliflower Soup?

I do think this soup is best with sharp cheddar, and we used a combination of white and yellow sharp cheddar which made the soup amazing. But no worries if you have a different type of cheese on hand! Whether you use less or more cheese than I did or use a different type of cheese if that’s what you have on hand, I bet you’ll love this soup if you try it!

Is Cheesy Broccoli Cauliflower Soup low in carbs?

It took some experimenting to come up with a broccoli-cheese soup that was mostly thickened with cauliflower, and I got inspiration from some soups I saw online. My original recipe used cauliflower, but for the Instant Pot version we switched it out for frozen cauliflower rice, which worked perfectly and saved some prep time. We did thicken the soup with just one tablespoon cornstarch, which gave a nice texture and only added 1 carb per serving (for a total of 10 net carbs), but you can definitely make it without the cornstarch if you prefer. I also added barely-cooked broccoli florets at the end for a little more texture.

Why I Love My Immersion Blender!

I think that if you’re going to try making a pureed soup that’s mostly thickened with the ingredients, using an Immersion Blender (affiliate link) to puree the hot soup is going to be the easiest method, and will also give the best results. (Pureeing hot soup in a blender or food processor is possible, but it’s not easy.)

More Cheesy Soups to make in the Instant Pot?

Instant Pot Low-Carb Loaded Cauliflower Soup and Cheesy Cauliflower Soup with Bacon and Green Chiles are two more soup recipes for everyone who likes plenty of cheese!

Cheesy Broccoli and Cauliflower Soup collage of Instant Pot version

How to Make Instant Pot Cheesy Broccoli Cauliflower Soup:

(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)

  1. Take cauliflower rice out of the freezer and let it start to thaw on the counter. 
  2. Heat olive oil in the Instant Pot on SAUTE, medium heat. Add onion and cook 2-3 minutes.
  3. Add minced garlic, thyme, Spike Seasoning, and a little salt and cook 2-3 minutes more.
  4. Chop up 4 cups broccoli (stems and florets) and + 2 cups broccoli florets.
  5. Add the 4 cups chopped broccoli, cauliflower rice,  and chicken or vegetable broth to the Instant Pot.
  6. Lock the lid and set the Instant Pot to MANUAL, high temperature, 3 minutes.
  7. When time is up let it natural release for 3 minutes and then release the pressure.
  8. Puree soup with an Immersion Blender (affiliate link) until it’s fairly smooth.
  9. Set Instant Pot to SAUTE, medium heat. Add the heavy cream (or half and half or milk) and let it heat to a very low simmer.
  10. When soup is barely simmering, mix 1 T cornstarch with 1 T water and stir into soup. (Just skip this if you don’t mind a slightly thinner soup.)
  11. We used equal amounts of sharp white cheddar and sharp yellow cheddar, but you can use all one kind of cheese.
  12. Stir cheese into the soup and let it melt completely. (Be sure the soup has stopped simmering when you add the cheese.)
  13. While cheese melts, microwave the broccoli for 1-2 minutes, until it’s as soft as you prefer.
  14. Stir cooked broccoli pieces into the soup. Taste for seasoning and add fresh ground black pepper (and salt if desired.)
  15. Serve hot, with more cheese to add at the table as desired.

Cheesy Broccoli and Cauliflower Soup in two soup bowls with cheese added

More Low-Carb Instant Pot Soups:

Check out Low-Carb and Keto Instant Pot Soups and 50 Low-Carb Instant Pot Soup Recipes to see lots more amazing ideas for low-carb soup made in the Instant Pot!

Weekend Food Prep:

This recipe has been added to a category called Weekend Food Prep  where you’ll find recipes you can prep or cook on the weekend and eat during the week!

Cheesy Broccoli and Cauliflower Soup shown in two serving bowls
Yield: 8 servings

Cheesy Broccoli Cauliflower Soup

Prep Time 40 minutes
Cook Time 20 minutes
Total Time 1 hour

Cheesy Broccoli Cauliflower Soup is an amazing low-carb soup that's loaded with cheesy broccoli flavor, and this recipe can be made in the Instant Pot or on the stove.

Ingredients

  • 2 tsp. olive oil
  • 1 onion, chopped small
  • 2 tsp. minced garlic
  • 1 tsp. dried thyme (see notes)
  • 2 tsp. Spike Seasoning (see notes)
  • 1/2 tsp. salt (more or less to taste)
  • 4 cups broccoli stems and florets + 2 cups chopped broccoli florets
  • 8 oz. (2 cups) frozen cauliflower rice
  • 4 cups low-sodium chicken or vegetable broth
  • 1 cup heavy cream (see notes)
  • 1 T cornstarch + 1 T water (optional)
  • 1 cup grated sharp white cheddar
  • 1 cup grated sharp yellow cheddar
  • black pepper to taste
  • additional grated cheese to add at the table (optional)

Instructions

  1. Take cauliflower rice out of the freezer and let it start to thaw on the counter, or cut two generous cups chopped cauiflower if you prefer. (You can also microwave the cauliflower rice for a minute or so. That will speed up the cooking time in the Instant Pot.)
  2. Heat olive oil in the Instant Pot on SAUTE, medium heat. Add onion and cook 2-3 minutes.
  3. Add minced garlic, thyme, Spike Seasoning, and a little salt and cook 2-3 minutes more.
  4. While onion and spices cook, chop up 4 cups broccoli (stems and florets) and + 2 cups broccoli florets.
  5. Add the 4 cups chopped broccoli, cauliflower rice,  and chicken or vegetable broth.
  6. Lock the lid and set the Instant Pot to MANUAL, high temperature, 3 minutes.
  7. When time is up let it natural release for 3 minutes and then release the pressure carefully.
  8. Puree the soup carefully with an Immersion Blender (affiliate link) until it's fairly smooth.
  9. Set Instant Pot to SAUTE, medium heat. Add the heavy cream (or half and half or milk) and let it heat to a very low simmer.
  10. When soup is barely simmering, mix 1 T cornstarch with 1 T water and stir into soup. Cook until it thickens a bit. (Just skip this if you don't mind a slightly thinner soup.)
  11. We used equal amounts of sharp white cheddar and sharp yellow cheddar, but you can use all one kind of cheese if that's what you have.
  12. Stir cheese into the soup and let it melt completely. 
  13. While cheese melts, microwave the 2 cups of broccoli for 1-2 minutes, until it's as soft as you prefer.
  14. Stir the cooked broccoli pieces into the soup. Taste for seasoning and add fresh ground black pepper (and salt if desired.)
  15. Serve hot, with more cheese to add at the table as desired.

STOVETOP INSTRUCTIONS:

  1. Thaw cauliflower rice on the counter or cut up chopped cauliflower same as above.
  2. Heat olive oil in Heat olive oil in large heavy soup pan over medium heat. Add onion and cook 2-3 minutes.
  3. Add minced garlic, thyme, Spike Seasoning, and a little salt and cook 2-3 minutes more.
  4. While onion and spices cook, chop up 4 cups broccoli (stems and florets) and + 2 cups broccoli florets.
  5. Add the 4 cups chopped broccoli, cauliflower rice,  and chicken or vegetable broth to the soup pot. Let the soup simmer on medium-low heat about 20-25 minutes (or until the broccoli and cauliflower are both very tender.
  6. Turn off heat and puree the soup carefully with an Immersion Blender until it's fairly smooth.
  7. Turn stove back on to medium heat. Add the heavy cream (or half and half or milk) and let it heat to a very low simmer.
  8. When soup is barely simmering, mix 1 T cornstarch with 1 T water and stir into soup. Cook until it thickens a bit. (Just skip this if you don't mind a slightly thinner soup.)
  9. Turn heat to very low, then stir the cheese into the soup and let it melt completely. (Be sure soup is not boiled when cheese is added.)
  10. While cheese melts, microwave the 2 cups of broccoli for 1-2 minutes, until it's as soft as you prefer.
  11. Stir the cooked broccoli pieces into the soup. Taste for seasoning and add fresh ground black pepper (and salt if desired.)
  12. Serve hot, with more cheese to add at the table as desired.

Notes

Use ground thyme if you have some. Use any all-purpose seasoning blend if you don't have Spike.

I used heavy cream, but use half and half or milk if you prefer if you prefer.

Recipe created by Kalyn with inspiration from Cream of Broccoli and Cheese Soup at Soup Chick and Roasted Broccoli and Cheddar Soup from Closet Cooking.

Nutrition Information:

Yield:

8

Serving Size:

1

Amount Per Serving: Calories: 300Total Fat: 23gSaturated Fat: 13gUnsaturated Fat: 7.7gCholesterol: 66mgSodium: 826mgCarbohydrates: 15gFiber: 4.8gSugar: 3.7gProtein: 14g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

Did you make this recipe?

Did you make this recipe? Please leave a star rating (under the PRINT button in the recipe) or share a photo of your results on Instagram! THANKS!

Cheesy Broccoli and Cauliflower Soup shown in two serving bowls with extra cheese on top and on the side.

Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Cheesy Broccoli Cauliflower Soup is great for low-carb diets, although you might want to skip the optional cornstarch for strict low-carb. Without cornstarch the soup has about 9 net carbs per serving, which might work for Keto for some people. The original South Beach Diet would recommend low-fat cheese and low-fat milk to make this soup lower in saturated fat, and the soup with the optional cornstarch would be phase 2 or 3 for South Beach. I’m not sure how the low-fat cheese will melt in the soup and personally I’d use regular cheese and make this an occasional treat if you’re following South Beach.

Find More Recipes Like This One:
Use Soup Recipes or Instant Pot Recipes to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.

Historical Notes for this Recipe:
This Broccoli Cauliflower Soup recipe was posted in 2017. It was last updated with an option to use the Instant Pot and a few minor changes to the recipe in 2023.

Pinterest image of Cheesy Broccoli Cauliflower Soup

Share This: