First Step: Roast the Cauliflower
Preheat your oven to 425–450°F (220–230°C). Toss cauliflower florets with 2 tablespoons of olive oil, a light sprinkle of salt, and freshly ground black pepper. Spread evenly on a rimmed baking sheet lined with parchment paper or a silicone mat. Add smashed garlic cloves with skins on if desired to roast alongside. Roast for 25–35 minutes, turning halfway through, until the florets are tender and caramelized at the edges. Remove the garlic skins once cooled if used. Save some roasted florets for garnish or adding back into the soup for texture.

Second Step: Sauté Aromatics
While the cauliflower roasts, heat the remaining 1 tablespoon of olive oil in a large soup pot over medium heat. Add the chopped red onion and ¼ teaspoon salt. Cook gently for 5–8 minutes until softened and translucent. Add pressed or minced garlic (or peeled roasted garlic) and cook for an additional 1 minute until fragrant.

Third Step: Combine and Simmer
Add the roasted cauliflower (except for reserved florets) to the pot along with 2–3 sprigs of fresh thyme if using. Pour in 4 to 4½ cups of vegetable broth, bring the mixture to a simmer over medium-high heat. Reduce heat and let it simmer gently for 15–20 minutes to blend the flavors.

Fourth Step: Blend the Soup
Remove the thyme sprigs. Carefully transfer the soup in batches to a blender along with butter or soaked cashews for creaminess. Blend until completely smooth and creamy. Return the blended soup to the pot.

Fifth Step: Season and Adjust
Add fresh lemon juice and a scant ¼ teaspoon of ground nutmeg to the soup. Blend or stir to combine and adjust seasoning with additional salt, lemon juice, or pepper as needed for balanced flavor.

Final Step: Serve and Garnish
Serve the roasted cauliflower soup hot, garnished with reserved roasted cauliflower florets and finely chopped fresh herbs such as parsley, chives, or thyme. Optionally drizzle with coconut milk or your favorite creamy topping to add richness and complexity. This soup pairs beautifully with crusty bread or a light salad for a complete meal.