Preheat the oven to 425 degrees.

Remove the leaves and trim the stem of the cauliflower but leave the core intact. With a sharp slicing knife, cut the whole cauliflower in large (½-inch-thick) slices. Don’t worry if the slices fall apart; they’ll look like snowflakes. Place the cauliflower on a sheet pan, drizzle with 3 tablespoons of olive oil, and sprinkle with ¾ teaspoon salt and ¼ teaspoon pepper. Roast the cauliflower for 15 minutes.

Toss the panko with 1 tablespoon of olive oil, sprinkle on the cauliflower, and roast for another 10 to 15 minutes, until tender and browned. Sprinkle with the Parmesan and roast for another minute or two. Immediately, scrape the pan with a metal spatula and toss the cauliflower and Parmesan. Serve hot or at room temperature.