Roasting vegetables until they caramelize intensifies their flavor and adds an additional layer of rich flavor to this Roasted Cauliflower Leek and Potato Soup.
Cauliflower and potatoes are pretty bland on their own. Roasting them activates the Maillard Reaction, which concentrates the natural sugars in the vegetables adding a toasted nutty flavor.
Love roasted vegetables? Try this Foil-Free Roasted Garlic.
If you love this creamy cauliflower soup as much as I do you might also be interested in these recipes for Roasted Tomato and Herb Soup, Cream Free Leek and Potato Soup, Winter Pork Stew, Chili with Bell Peppers, Pork Black Bean and Pumpkin Stew, or Dutch Oven Beef Stew.
Why You Will Love This Recipe
- This recipe is easy to double or triple and freezes really well for an even quicker meal later.
- I love making this creamy cauliflower leek soup as a weeknight meal. It does take an hour to make but the best part is so much of that time is pretty hands-off. Once the vegetables are chopped and in the oven, you are free to relax.
- This rich creamy soup is made without heavy cream which helps cut down the calories.
- By substituting cauliflower for some of the potatoes you end up with a lighter but still delicious version of classic potato soup.
You will need the following ingredients to make these tangy Cauliflower Leek and Potato Soup.
Potatoes: When making a creamy soup I prefer to use starchy potatoes like russet potatoes. Unlike other waxier potatoes, they don't hold their shape when they are cooked, making the soup nice a creamy without having to add cream.
Russet potatoes are also delicious when smoked and turned into these BBQ Pulled Pork Potato Skins.
Cauliflower: Cauliflower is delicious and so versatile. It is basically a blank canvas.
It can be found year-round in the grocery store and kept in your refrigerator for up to two weeks making it a great fresh vegetable option for the end of your weekly meal plan.
Leeks: Leeks look like overgrown green onions. When purchasing leeks look for ones that are about an inch in diameter and have a long white to the pale green shaft.
Leeks have a mild, onion-like taste. Typically just the white and light green parts of a leek are eaten. The darker green parts have plenty of flavor and are great for making homemade chicken stock.
Garlic: Chopping garlic is one of my least favorite kitchen tasks. For this soup, whole cloves of garlic are roasted and then pureed, with no chopping necessary.
Olive Oil: Coating the vegetables in olive oil before roasting them will help to encourage browning.
White Wine: White wine like other acids helps to brighten the flavor of this soup.
Butter: Adding butter right before blending the soup will make it creamier and richer tasting.
See the recipe card for full information on ingredients and quantities.
Substitutions and Variations
Leeks: If you don't have any leeks, you can substitute white or yellow sweet onion.
Chicken Broth: To make this soup vegetarian substitute vegetable broth for the chicken broth.
Butter: To make this soup vegan and dairy-free substitute olive oil for the butter.
Fresh Herbs: Because potatoes and cauliflower are pretty bland on their own feel free to cook with any fresh herbs you have in your refrigerator.
Step by Step Directions
Preheat the oven to 425°F (220°C). Line a large rimmed sheet pan with parchment paper.
In a large bowl, toss the potatoes, cauliflower florets, leeks, celery, and garlic with olive oil. Season with salt and black pepper to taste.
Arrange the vegetables on the baking sheet in a single layer.
Roast the vegetables until the have caramelized and are golden brown. This should take approximately 25 to 35 minutes. Toss the vegetables halfway through the bake time to ensure even browning.
Reserve ¼ of the vegetables for topping the finished soup.
Tip: Dry the vegetables thoroughly to allow the oil to coat them properly and encourage browning.
To learn more about roasting vegetables read this post "Tips for Perfectly Roasted Vegetables."
Transfer the remaining vegetables to a large soup pot and add the wine. Simmer for 2-3 minutes over medium-low heat. Add the chicken broth and dried sage and simmer for an additional 10 minutes.
Add the butter and blend the soup with an immersion blender. If the soup is too thick add additional chicken stock until you reach your desired consistency. Taste and adjust the seasoning, if necessary.
Tip: If you don't have an immersion/stick blender you can also puree the soup in a food processor or blender. If you're using a blender, purée the soup in batches. Don't fill the blender more than a third full at a time, and remember to hold down the lid while the blender is going.
Serve immediately garnished with reserved vegetables, fresh herbs, and grated Parmesan cheese.
Customize this soup and make it your own by varying the toppings you choose. Some of my favorites include:
- Crispy Bacon
- Diced Green Onions
- Fresh Parsley
- Shredded Cheese: Cheddar and Parmesan are my favorites.
- Dollop of Sour Cream
I also like to serve this soup with crusty bread, garlic bread, rolls or these Ham and Cheese Sourdough Scones to sop up every last bit and a crispy side salad like this Kale Apple Salad with Honey Dressing.
Storage and Freezing Instructions
If you have leftover soup, allow the soup to come to room temperature and then store it in an airtight container in the refrigerator for 3-4 days.
To Freeze: Allow the soup to come to room temperature and then transfer it to an airtight container or zip-top bag. Label the container with the contents and date. Then freeze the soup for up to three months.
Sometimes there is a little separation in soup once you freeze and defrost it. If this happens, just purée the soup again until smooth.
For more tips on freezing soups and stews read this post: How to Freeze Beef Stew.
To Reheat: If you are in a hurry, you could simply microwave a bowl of this soup for a couple of minutes.
But for the best results, especially if I am reheating more than one serving, I prefer to heat this soup on the stovetop in a saucepan over medium heat.
Cauliflower will last in the refrigerator for two weeks. If you see brown spots on your cauliflower they are a sign it is going bad and you need to use it soon. You can trim the brown spots off if there are only a few but the longer you wait the more they will spread, changing the texture of the cauliflower.
1. Rinse the leeks under water to remove visible dirt or sand.
2. Cut off the roots and the dark green tops of the leeks and slice the leeks in half lengthwise.
3. Chop the leek halves into semi-circles.
4. Rinse the chopped leeks in a bowl of cold water. Use your hands to agitate the leeks and dislodge any dirt or sand that may be clinging to them.
5. Pour the leeks into a colander to drain.
Nope. To get the best caramelization you want your cauliflower to be dry before roasting it in the oven.
Adjust the amount of chicken stock. If you prefer a thicker soup use less chicken stock. If you prefer a thinner soup add a little more. If you accidentally add too much chicken stock, make a slurry of two parts liquid to one part cornstarch. Stir the slurry into the soup and allow it to simmer until it thickens.
- Cut the vegetables into uniform sizes to ensure even roasting.
- Don't crowd the roasting pan. Make sure there is enough room for air to circulate around the vegetables. Otherwise, the vegetables will steam rather than roast.
- To make this soup vegetarian, replace the chicken stock with vegetable stock.
- If you don't have an immersion/stick blender you can also puree the soup in a blender. If you're using a blender, purée the soup in batches. Don't fill the blender past the maximum fill line, the volume of the soup will expand as you blend, and open the vent to allow the steam to escape.
- If you prefer a thicker soup reduce the amount of chicken stock. If you prefer a thinner soup increase the amount of chicken stock.
Let me know what you thought of this easy homemade soup recipe in the comments below. What are your favorite toppings?
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Roasted Cauliflower Leek and Potato Soup
- 1 large russet potato peeled and cut into 1 inch pieces
- ½ a large head of cauliflower cut into 1 inch pieces
- 4 large leeks cleaned and cut into ¼ inch slices
- 3 stalks of celery cut into ½ inch slices
- 4 cloves of garlic
- ¼ cup olive oil
- salt and pepper
- ½ cup dry white wine
- 6 cups chicken stock
- 1 teaspoon dried sage
- 2 tablespoons unsalted butter
- For garnish: fresh dill or thyme and grated Parmesan cheese
- Preheat the oven to 425°F (220°C). Line a large rimmed baking sheet with parchment paper.
- In a large bowl, toss the 1 large russet potato, ½ a large head of cauliflower , 4 large leeks, 3 stalks of celery, and 4 cloves of garlic with ¼ cup olive oil. Season with salt and pepper to taste.
- Arrange the vegetables on the baking sheet in a single layer. Roast the vegetables until the have caramelized and are golden brown. This should take approximately 25 to 35 minutes. Toss the vegetables halfway through the bake time to ensure even browning.
- Reserve ¼ of the vegetables for topping the finished soup. Transfer the remaining vegetables to a large pot and add the ½ cup dry white wine. Simmer for 2-3 minutes over medium-low heat.
- Add the 6 cups chicken stock and 1 teaspoon dried sage and simmer for an additional 10 minutes.
- Add the 2 tablespoons unsalted butter and blend the soup with an immersion blender or transfer to a blender and puree in small batches.
- If the soup is too thick add additional chicken stock until you reach your desired consistency. Taste and adjust the seasoning, if necessary.
- Serve immediately garnished with reserved vegetables, fresh herbs, and grated Parmesan cheese.