Place a rack in upper third of oven; preheat to 425°F. Halve squash1 lengthwise and scoop out seeds with a large spoon. Using a peeler, remove skin and white flesh below (you should reach the deep orange flesh). Rub all over with oil1 tablespoon; season with salt and pepper. Roast in a baking dish just large enough to hold halves side by side until beginning to soften (a paring knife should easily slip in only about 1/4"), 15–18 minutes.