Preheat the oven to 425°F. Using a small sharp knife, and starting at the base of the Romanesco cauliflower, cut off the florets, or cut regular cauliflower into 1-inch florets. Place the cauliflower in a large bowl. Add 1½ tablespoons of the olive oil and sprinkle with salt and pepper. Toss to coat. Transfer the cauliflower to a heavy, rimmed baking sheet. Place in the oven and roast until the cauliflower is brown in spots and almost tender, stirring once, about 25 minutes. Remove from the oven.

Add the pasta to a large pot of boiling salted water, and cook until just tender but still firm to the bite, about 10 minutes.

While the pasta cooks, heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat. Add the shallots and red pepper flakes and sauté until the shallots start to brown, about 4 minutes. Add the cauliflower and cook until hot, about 3 minutes.

Ladle off 1 cup of water from the pasta and reserve; drain the pasta. Add the pasta, and olives to the skillet. Add the reserved 1 cup pasta cooking water and stir over medium heat until the liquid thickens slightly and the mixture is blended, about 30 seconds. Mix in the parsley, 1/3 cup cheese, and 1 to 2 tablespoons extra-virgin olive oil. Season to taste with salt and pepper. Divide the pasta between 2 warmed plates. Serve right away, passing more cheese at the table.