Easy Roasted Cauliflower Soup
- PREP 20min
- COOK 30min
- TOTAL 50min
For this easy cauliflower soup recipe, we roast a whole head of cauliflower until golden brown and then blend it with onion, parmesan cheese, and broth until silky smooth. This healthy soup is creamy, decadent, and delicious! For more crunch, try serving this soup topped with our homemade garlic croutons.
You Will Need
1 large head cauliflower, about 2 pounds
4 tablespoons olive oil
1 teaspoon fresh thyme leaves or 1/4 teaspoon dried thyme
4 garlic cloves, left unpeeled
1/2 large onion, chopped, about 1 ¼ cups
1 celery stalk, chopped, about 1/2 cup
Pinch crushed red pepper flakes, optional for heat
4 cups (946ml) vegetable broth or chicken broth
2 tablespoons butter
1 tablespoon fresh lemon juice, or more if needed
1/4 cup grated parmesan cheese, plus more for serving, optional (1/2 ounce)
Directions
Preheat the oven to 425°F (220°C) and prepare a baking sheet. We roast the cauliflower directly on the baking sheet, but for easy cleanup, line it with parchment paper or a silicone baking mat.
Remove the larger leaves from the cauliflower and leave the core intact. (You can save the leaves to blend into the soup later.)
Slice the cauliflower in half and cut it into 3/4-inch thick slices.
Drizzle two tablespoons of olive oil onto the baking sheet, then arrange the cauliflower on top of the oil.
Add the unpeeled garlic cloves (they will roast in their peels) and the thyme, then drizzle over two more tablespoons of olive oil. Move the cauliflower slices around so they each have a chance to touch some oil.
Roast for 20 minutes or until the bottom of each slice looks well browned. Flip each piece, and then roast for 5 minutes more.
Melt two tablespoons of butter in a deep soup pot over medium heat. Then, stir in the onions, celery, pinch of red pepper flakes, and 1/4 teaspoon salt. Cook until softened, about 5 minutes.
When they are cool enough to handle, squeeze the garlic from inside each clove and place it in the soup pot. Discard the garlic peel.
Transfer the roasted cauliflower to the pot and pour in the broth. If you saved any cauliflower leaves from earlier, add them to the pot. Bring to a simmer and cook for 10 minutes.
Turn off the heat, and add the cheese and two tablespoons of lemon juice.
Blend the soup until smooth. An immersion blender is the easiest, or you can use a blender. If you use a regular blender, it is best to blend in batches and fill the blender less than you usually would since the soup is so hot. We like to remove the lid’s center insert and cover it with a kitchen towel while blending. This helps to release some of the steam and prevents the blender lid from popping off (which can be a big, hot mess).
Taste the soup and add more lemon juice, salt, and pepper until the flavor pops (it should make you smile). Serve with more cheese, a few grinds of black pepper, and a drizzle of olive oil on top.
Adam and Joanne's Tips
- Storing: This cauliflower soup lasts in your refrigerator for up to 5 days. It can also be frozen for up to one month, probably longer.
- Soup is too thick: Add 1/4 cup to 1 cup of water. Add enough water to achieve your preferred thickness. The water will not water down the flavor of your soup, but if you are concerned or have more on hand, you can use stock or broth.
- Vegetarian adaptations: Use vegetable broth, a vegetarian-friendly cheese or leave it out altogether.
- Vegan adaptations: Use vegan broth, vegan butter and vegan cheese or a couple tablespoons of nutritional yeast instead (my preference).
- The nutrition facts provided below are estimates.