Adjust oven rack to upper-middle position and heat oven to 500 degrees. Quarter cabbage through core and cut each quarter into 2 wedges, leaving core intact. Arrange wedges, 1 flat side down, on rimmed baking sheet. Brush 1½ tablespoons oil on exposed cut sides of wedges and sprinkle with ½ teaspoon salt. Flip wedges so oiled sides are flush with sheet. Brush second cut sides with remaining 1½ tablespoons oil and sprinkle with pepper and remaining ½ teaspoon salt. Cover sheet tightly with aluminum foil and roast for 20 minutes.
Remove foil (be careful of escaping steam) and continue to cook until cabbage wedges begin to brown on underside, 5 to 10 minutes. Using tongs and thin metal spatula, flip each wedge. Roast until edges are very well browned and some leaves have crisped, 5 to 10 minutes. Transfer to serving platter, season with salt and pepper to taste, and serve.
