Step 1

For the Romesco sauce: In a food processor or a high-speed blender, combine all the sauce ingredients. Blend until the mixture is as smooth as possible. Transfer to small bowl. (You can prepare the sauce a day ahead; cover and refrigerate.)

Step 2

For the cauliflower: Preheat the oven to 400°F. Line a rimmed baking sheet with parchment paper.

Step 3

In a medium bowl, toss the cauliflower florets with the olive oil to coat. Spread the cauliflower florets on the prepared baking sheet and roast until tender and browned in spots, 25 to 30 minutes. Season with the salt and pepper.

Step 4

Spread the Romesco sauce on a platter and arrange the cauliflower on top. Sprinkle with the basil and serve. You can also toss the cauliflower in the sauce and garnish with basil before serving.