1. Preheat oven to 350°F. Spray 9×13-inch baking dish or gratin dish with cooking spray.
2. Toss pumpkin with garlic, parsley, sage, and salt and pepper to taste. Transfer to baking dish, and drizzle with olive oil.
3. Bake 1 hour, or until pumpkin begins to soften and brown around the edges, stirring occasionally. Toss with cheese and breadcrumbs. Bake 15 minutes more, or until top is golden brown.