Cauliflower Leek Soup

Name: Cauliflower Leek Soup
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: American
Ingredients: 3 tablespoons olive oil (or butter); 2 cups thinly sliced leeks; 2 teaspoons minced garlic; 4 cups finely chopped cauliflower florets (1 small head); 1 cup diced celery (1-2 large stalks); 1 teaspoon kosher salt; 3 tablespoons all purpose flour; 5 cups vegetable broth, reserve 1/2 cup; 1 1/2 tablespoons freshly squeezed lemon juice; Black pepper to taste; 2 tablespoons finely chopped parsley; 2 teaspoons finely chopped oregano

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This cauliflower leek soup is a creamy and comforting, but light spring soup! Best of all, it comes together in one pot and a blender. Just cook the vegetables, blend, and you're done in just about 30 minutes!

Overhead view of cauliflower leek soup in a bowl.

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Why We Love This Recipe
Ingredients
Ingredient Notes
How to Make This Cauliflower Leek Soup
Variations
Expert Tips and FAQs
Related Recipes
📖 Recipe
💬 Reviews

Why We Love This Recipe

Great use of spring produce: Leeks are one of our favorite spring produce items, and this soup is a great way to utilize them.
Naturally vegan/dairy free: This cauliflower leek soup doesn't contain any dairy! It's also easy to make gluten free with one simple swap.
Rich and creamy, but light: This cauliflower leek soup feels decadent, but it's actually super nutritious and packed with vegetables! Perfect for a chillier spring day when you still want comfort food, but not something quite as heavy.
Quick and easy: This recipe comes together in just a few simple steps in about 30 minutes.

Ingredients

Here's what you'll need to make this cauliflower leek soup:

Ingredient Notes

Cauliflower: You'll need 4 cups worth of chopped florets in this recipe, which is about equal to one small head of cauliflower.
Leeks: The traditional way to prepare leeks is by trimming the tough green leaves, and using the tender light green and white section. You can technically use the dark greens, you will just need to let them cook for longer before blending, as they take much longer to soften. We measure the leeks by cups in this recipe, since the size of each leek varies significantly.
- Note: thoroughly clean your leeks before using – they hold a lot of dirt!
Oil: Olive oil, butter and vegan butter are all interchangeable in this recipe.
Flour: A small amount of all purpose flour helps make this cauliflower leek soup extra thick and creamy, without any added dairy. Feel free to use gluten free all purpose flour to keep this recipe free from gluten.
Vegetable broth: Want to make your own from leftover vegetable scraps? Try this recipe.
Herbs: We used fresh oregano and parsley in this recipe, but it would also be delicious with other herbs like dill, tarragon, basil and more. While we prefer using fresh herbs for maximum flavor, you can sub dried if needed. Reduce the quantity to ⅓-1/4 if using dried.
Lemon juice: Freshly squeezed is always best for freshest flavor!

How to Make This Cauliflower Leek Soup

(1) Add olive oil to a large pot over medium heat. Add leeks and garlic and sauté for 5-6 minutes, until softened.

(2) Add cauliflower, celery and ¾ teaspoon of salt, stir and continue cooking for 5-7 minutes.

On the left: sauteed leeks and garlic in pot. on the right: added in cauliflower and celery.

(3) Whisk flour into ½ cup of vegetable broth until no lumps remain and set aside.

(4) Add remaining broth and lemon juice to the soup. Bring to a boil, then reduce heat to low and simmer for 20 minutes.

on the left: flour and broth mixture in bowl. on the right: pouring broth into soup pot.

(5) Transfer soup to blender along with parsley and oregano. Blend until completely smooth.

(6) Remove to pot and whisk in flour/broth mixture. Heat over medium high until soup thickens (about 5 minutes). Season with additional salt and pepper.

Before and after blending cauliflower leek soup.

Variations

Add in a can of white beans: To add some protein (and a bit of extra heft) to this cauliflower leek soup, add in a can of drained white beans before blending.
Cauliflower Leek Potato Soup: For an extra creamy soup, sub part (about half) of the cauliflower with yellow potatoes. They will make for a thicker base and add a bit of extra heft to the recipe.
Broccoli Cauliflower Leek Soup: Sub half of the cauliflower for broccoli if preferred. This will also make for an extra green soup!
Make it extra creamy: Feel free to add in a splash of heavy cream (we use a vegan alternative) or even coconut milk before blending for an extra rich soup.
Top it with bacon: Our crispy mushroom "bacon" is our go-to, but of course regular works for non vegans!
Add extra vegetables: Add in greens, like spinach or kale before blending for more nutrients + an extra green color. You can also add in other vegetables like broccoli, potatoes, parsnips, celery root, squash, or anything else you have on hand.

Expert Tips and FAQs

Regular blender vs. immersion blender: A regular blender will yield a creamier soup, but it can be a pain to transfer the hot soup from the pot to blender. An immersion blender is a great alternative, but the soup won't be quite as smooth. If using a regular blender, be careful of the hot steam, and make sure your blender is heat safe before using.
Make it gluten free: Substitute regular all purpose flour with a gluten free alternative.
Serve as a side dish or main: This is a pretty low calorie soup, so we prefer to serve it as a side dish, paired with other spring favorites like this asparagus potato salad or spring vegetable pasta. If serving it as a main dish, consider adding toppings.
Storage: let soup cool completely, then transfer to an airtight container and refrigerate for up to 5 days.
Freezer storage: You can also freeze this cauliflower leek soup for up to 6 months. Defrost in the refrigerator overnight, then heat gently on the stovetop until warm.

What part of the leek should you use for soup?

In most traditional culinary preparations, you should remove the tough, dark green leaves and just use the light green and white bulb. The dark green section tends to be much tougher and more bitter, which is why it's often not used. (However, you can use it in homemade vegetable broth!)

That being said, it's not unsafe to eat the dark green section – it just needs a little extra cooking time to soften. If you decide to use it, let the leeks sauté for 15 minutes before adding the cauliflower and celery.

How do you clean leeks?

Leeks are notorious for holding a lot of dirt in between each layer, so it's important to thoroughly clean them before using. To do so, trim the upper dark green leaves, then slice the bulb in half lengthwise. Run under water, using your hands to separate the layers, to remove as much dirt as possible.

If they're still dirty, slice the leeks, then transfer to a colander and rinse a second time.

How do you slice leeks?

Remove the tough dark green leaves (see above for why) as well as the root end. Slice the bulb (the light green and white section) in half lengthwise, rinse, then set cut side down on cutting board. Slice thin strips. For finely diced leeks, quarter the bulb lengthwise before thinly slicing. Check out this article for more info on how to prepare leeks.

Overhead view of cauliflower leek soup in a bowl garnished with herbs.

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