Recipes
Roasted Cauliflower Soup Recipe
This roasted cauliflower soup gets its deep flavor from browned cauliflower and garlic, then blends into a smooth, cozy bowl with a simple vegetable-broth base. It is easy to adjust with milk, cream, or a dairy-free substitute.
Overview
This roasted cauliflower soup recipe uses high-heat roasting to give the cauliflower browned edges and a sweeter, more savory flavor than simmering alone. Onion and garlic roast alongside it, then everything is blended with vegetable broth until smooth.
A small potato gives the soup body without requiring much cream, although a splash of milk or cream makes the finish especially silky. Serve it as a light main dish with crusty bread or alongside a crisp salad.
Ingredients
- 1 large head cauliflower, about 2 pounds (900 g), trimmed and cut into 1 1/2-inch florets
- 1 medium yellow onion, peeled and cut into 1-inch chunks
- 4 garlic cloves, peeled
- 3 tablespoons olive oil, divided
- 1 teaspoon kosher salt, plus more to taste
- 1/2 teaspoon black pepper
- 1 medium russet or Yukon Gold potato, peeled and cut into 1-inch cubes
- 4 cups (960 ml) low-sodium vegetable broth, plus more if needed
- 1/2 teaspoon dried thyme, or 1 teaspoon fresh thyme leaves
- 1/2 cup (120 ml) heavy cream, whole milk, or unsweetened oat milk, optional
- 1 teaspoon fresh lemon juice, plus more to taste
- Chopped chives, toasted breadcrumbs, or a drizzle of olive oil, for serving, optional
How to make it
Heat the oven and prepare the vegetables. Position a rack in the center of the oven and heat it to 425°F (220°C). Line a large, rimmed baking sheet with parchment if desired. Spread the cauliflower, onion, and garlic over the sheet. Toss with 2 tablespoons of the olive oil, the salt, and black pepper. Keep the vegetables in one layer with a little space between pieces.
Roast until browned and tender. Roast for 25 to 35 minutes, stirring once after about 18 minutes. The cauliflower is ready when the florets are tender when pierced with a knife and several edges are deeply golden brown. The onion should be soft, and the garlic should be tender and lightly browned. If the cauliflower is tender but pale, roast it for 5 to 10 minutes longer.
Cook the potato. While the vegetables roast, heat the remaining 1 tablespoon olive oil in a large pot over medium heat. Add the potato and cook for 2 minutes, stirring so it does not stick. Pour in the vegetable broth and add the thyme. Bring to a gentle boil, then reduce the heat and simmer for 10 to 12 minutes, until the potato can be easily crushed against the side of the pot with a spoon.
Combine the roasted vegetables and broth. Add the roasted cauliflower, onion, and garlic to the pot. Simmer gently for 3 minutes so the flavors combine. Remove the pot from the heat and let it cool for 5 minutes before blending.
Blend the soup carefully. Blend in batches in a countertop blender, filling the jar no more than halfway. Remove or loosen the center cap and cover the opening with a folded kitchen towel so steam can escape. Start on low speed and increase gradually, blending until smooth. Alternatively, use an immersion blender directly in the pot, moving it through the soup until no large pieces remain.
Finish and season. Return the blended soup to low heat. Stir in the cream, milk, or oat milk if using; do not let the soup boil after adding dairy. Stir in the lemon juice, then taste and adjust with more salt, pepper, or lemon. If the soup is thicker than you like, add warm broth 2 tablespoons at a time until it reaches a pourable, velvety consistency.
Serve. Ladle the soup into bowls and finish with chopped chives, toasted breadcrumbs, or a small drizzle of olive oil. For a more substantial meal, serve it with bread or a salad such as roasted beet salad.
Frequently asked questions
Can I make roasted cauliflower soup without dairy?
Yes. Omit the cream or use unsweetened oat milk. The roasted cauliflower and potato provide plenty of body, so the soup will still be smooth and creamy when blended.
Why does my roasted cauliflower soup taste bland?
Roasting creates flavor, but the soup still needs enough salt and acidity. Taste after blending and add salt gradually, followed by a small amount of lemon juice to brighten the finished soup. Pale cauliflower can also produce a milder soup, so roast until the edges are clearly golden.
How can I make the soup completely smooth?
Blend it in batches with a countertop blender, or use an immersion blender for several minutes. For an especially silky texture, pass the blended soup through a fine-mesh strainer, although this is optional.
Can I use frozen cauliflower?
Yes, but do not thaw it first. Spread the frozen florets out well on the baking sheet and expect them to release more moisture, which may add 10 to 15 minutes to the roasting time. Roast until the pieces are tender and browned rather than simply soft.
Can I freeze roasted cauliflower soup?
Freeze the soup before adding cream, milk, or oat milk for the best texture. Cool it promptly, transfer it to airtight freezer containers leaving room for expansion, and freeze for up to 3 months. Thaw in the refrigerator, reheat gently, then add the dairy or milk and adjust the seasoning.
