Roasted Cauliflower with Kalamata Vinaigrette

Preheat oven to 450°F with rack in lower third.

Cut cauliflower lengthwise into 3/4-inch-thick slices. Put in a large 4-sided sheet pan and toss with 2 tablespoon oil and 1/2 teaspoon each of salt and pepper. Roast, turning once or twice, until golden and just tender, about 25 minutes.

While cauliflower roasts, mince and mash garlic to a paste with a pinch of salt, then whisk together with lemon juice, remaining 2 tablespoons oil, olives, 1/8 teaspoon salt, and 1/2 teaspoon pepper. Serve cauliflower drizzled with Kalamata vinaigrette.