This cauliflower potato leek soup is a satisfying and hearty dish that won't weigh you down. The cauliflower creates a rich, creamy texture and eliminates the need for heavy cream or cheese.
I love potato and leek soup because it's easy to make and takes only a handful of simple, whole ingredients. While this version has an extra step - roasting cauliflower - it's worth the effort for the extra nutrients, vegetables, and heartiness. Plus, without the dairy, aside from a bit of butter, it won't leave you feeling bloated either.
While the recipe does contain butter, you can easily substitute it with an alternative and make it completely dairy-free and vegan.
I make some kind of soup just about every week and if you enjoy soup as much as I do, check out some of my other recipes, such as this tasty seafood newburg soup, a filling lentil and rice soup, and another variation on the classic leek potato soup, a celery and leek soup.
Jump to:
🥔Ingredients
This soup takes just eight ingredients. No fancy spices or anything hard to find.
- olive oil - your favorite variety works great
- cauliflower - pick one that's creamy white, without many blemishes
- leeks - look for leeks that are firm, with dark green tops and white bottoms
- butter - make it dairy free and use more olive oil, if needed
- garlic - what's a soup without a bit of garlic?
- thyme - fresh is best, but dried will work
- potatoes - Russet or a Yukon Gold
- broth - vegetable or chicken, I look for low sodium since I like to salt food myself
- optional toppings - such as crumbled bacon, cheese, or croutons
See the recipe card below for the quantities.
🔪Instructions
Roasting the cauliflower may seem like an unnecessary step, but I think it really helps to add even more flavor. And if you can get it in the oven right off the bat, it'll be ready to go by the time the soup is ready to puree. So you're not really adding much extra time in the scheme of things.
But if you're in a rush and don't want to turn the oven on, fine. Just add it in with the potatoes. You'll still get the creamy texture in the end.
Preheat the oven to 425 F. Roughly chop the cauliflower. Spread it on a baking sheet and toss with the oil and ½ teaspoon of salt. Roast for about 18 minutes.
Meanwhile, slice the white and light green parts of the leek, and peel and chop the potatoes. Mince the garlic and remove thyme leaves from the stems.
Give the leeks a good rinse and drain to remove any dirt or sand.
Add the potatoes and broth. Bring to a boil and simmer for about 10 minutes.
Off heat, use an immersion blender to carefully puree the soup until creamy.
In a Dutch oven, melt the butter. Add the leeks and saute until soft and creamy, about 10 minutes. Add the minced garlic, thyme, and ½ teaspoon of salt about halfway through.
Stir in the roasted cauliflower and add a few grinds of fresh black pepper.
Serve with your choice of toppings, such as bacon and additional thyme leaves.
Hint: Soups are made all the better by their toppings. A few ideas for this one:
- Chop a few slices of bacon and cook until crispy in a pan while the soup simmers.
- Set aside some of the roasted cauliflower and use it as a topping.
- Toss some cubed stale bread with a bit of oil and spices and cook them in a pan until browned and crispy for speedy croutons.
- Shredded cheddar cheese will melt beautifully on top, if you don't mind a bit of dairy.
- If you have extra thyme, but not time, a few small springs look great, if nothing else.
🥄Substitutions and Variations
A few ways to customize this cauliflower potato leek soup.
- Dairy-free and vegan - Simply swap the butter for olive oil.
- Dried thyme - Yes, dried thyme will work in place of fresh, though it likely won't add as much flavor. Use about a ⅓ as much.
- Not roasting the cauliflower - If you can't be bothered to roast the cauliflower, add it to the pot when you add the potatoes and cook until tender.
- Chunky version - You can actually skip the pureeing altogether if you don't want the soup creamy and just mash it up a bit with a potato masher. Though you won't get the benefit of the cauliflower's creaminess. I bet it would still be delicious, though.
🍲Equipment
There are two pieces of equipment that I think will make this soup easier, if not better.
First is a Dutch oven. I say it all the time, but a Dutch oven is a great investment. You don't need the high-end, (and yeah, overpriced) version, there are decent ones out there for about $50 and they'll last you for years. The heavy bottom helps prevent burning and retains heat well, not to mention they're great for going from the stovetop into the oven.
The second item is an immersion blender. Sure you could do this with a regular blender, but ladling soup into the blender is tedious, messy, and a bit dangerous if the soup is very hot. With an immersion blender, you can puree the soup right in the pot without having to wash a whole blender after. I recommend this one from Braun.
🥡Storage
Store leftover cauliflower potato leek soup in a container in the fridge for up to 4 days. I tend to store most of my leftovers in deli takeout containers like these.
🧂FAQ
Make sure to cook the potatoes all the way through before pureeing. Also, don't go overboard pureeing the soup. It doesn't have to be perfectly smooth. If it seems too thick, thin it out with more broth.
If you follow this recipe, it shouldn't be! But I have had bland leek and potato soups in restaurants, so I understand your concern. I think sometimes people just throw everything in a pot and boil it without taking the time to layer flavor by sauteing vegetables and seasoning first.
There aren't many ingredients here, so don't skip the salt, garlic, or thyme, as they add much to the flavor. Of course, taste your soup before serving and add more of those seasonings, if needed. And the worst case, if it's still bland, add a splash of acid, like vinegar, to boost the soup's flavor. Those toppings add flavor too, so definitely add a few of them if you feel something is lacking.
Of course! Do so in a small pot over low heat or loosely covered in the microwave until hot.
Cauliflower Potato Leek Soup
- Total Time: 40 minutes
- Yield: 4 servings 1x
- Diet: Vegetarian
Description
This cauliflower potato leek soup is a satisfying and hearty dish that won't weigh you down. The cauliflower creates a rich, creamy texture and eliminates the need for heavy cream or cheese.
Ingredients
- 1 tablespoon olive oil
- 1 small/medium cauliflower
- 1 teaspoon kosher salt
- 2 leeks
- 2 tablespoons butter
- 3 garlic cloves
- 1 tablespoon fresh thyme leaves
- freshly ground black pepper
- 5 cups vegetable broth
- 2 pounds of potatoes, such as Yukon gold or russet
- toppings, such as crumbled bacon, extra thyme leaves, or shredded cheese
Instructions
- Preheat the oven to 425 degrees F. Roughly chop up the cauliflower. You'll want about 5 cups. Spread out on a baking sheet with parchment and toss with the olive oil and ½ teaspoon salt. Place in the oven to cook for about 18 minutes or until golden and tender.
- Prep the other vegetables. Slice up the light green and whites of the leeks and give them a rinse. Peel and roughly chop the potatoes. Mince the garlic. Remove the thyme leaves from the stems.
- In a large pot or Dutch oven, heat the butter over medium heat. Add the leeks and saute for 5 minutes, stirring on occasion. Add the other ½ teaspoon of salt, the thyme leaves, the minced garlic, and a few grinds of black pepper. Cook another 5 minutes.
- Add the potatoes and broth to the pan. Bring to a boil and simmer over medium-low heat until the potatoes are soft, about 10 minutes.
- Add the roasted cauliflower to the pot. Then blend until no large pieces remain and the soup is mostly smooth.
- Taste the soup and add additional salt and pepper, to your liking. Serve with toppings of your choice.
- Prep Time: 20 minutes
- Cook Time: 20 minutes
- Category: Soup
- Method: Stove top
Keywords: leek soup, potato soup, cauliflower soup, leek and potato soup, soups
Jessica Edgerly Walsh
The kids weren't sure at first glance, but then proceeded to eat nothing else for dinner. I used a bit more thyme, but otherwise stuck to the recipe. It's definitely the epitome of happy, comfort food.
★★★★★
Steve
Happy to hear your family enjoyed the soup, Jess! Can never go wrong with more thyme. Thanks for sharing!