A few minutes under the broiler -- plus a heavy sprinkling of fontina cheese -- transforms sliced mushrooms into a flavorful (and deliciously gooey) side dish.
Preheat broiler. Arrange mushrooms in a single layer in a baking dish. Drizzle with oil, and sprinkle with 1/2 teaspoon salt and some pepper. Broil for 2 minutes. Remove dish from oven, and add thyme and cheese. Broil for 1 minute. Serve warm.