1-Preheat the oven: Start by preheating your oven to 425 degrees Fahrenheit and lining a rimmed baking sheet with parchment paper if you have it on hand. This helps create that essential caramelized flavor through roasting.

2-Roast the cauliflower: Toss the cauliflower florets with 2 tablespoons of extra-virgin olive oil and a bit of salt, then spread them out in a single layer on the baking sheet. Roast for 25 to 35 minutes, stirring halfway through, until they’re tender and have a nice golden color.

3-Sauté onions: While that’s happening, heat the remaining 1 tablespoon of extra-virgin olive oil in a soup pot over medium heat and add the chopped red onion with ¼ teaspoon salt, cooking for 5 to 7 minutes until it’s translucent.

4-Add garlic and broth: Next, add the garlic and cook for another 30 seconds until fragrant, then pour in the 4 cups of vegetable broth.

5-Combine and simmer: Reserve 4 cauliflower florets for garnish and add the rest to the pot, bringing everything to a simmer. Let it cook for 20 minutes, then cool slightly before blending.

6-Blend the soup: Transfer the mixture to a blender in batches, adding the unsalted butter, and blend until smooth.

7-Final touches: Finally, stir in the lemon juice and nutmeg, adjusting seasoning as needed, and serve with the reserved florets and chopped herbs.