Preheat oven to 325F. Lightly butter a shallow baking dish. Set aside.
Peel the squash and cut into 1-inch cubes. Toss with garlic, parsley, salt and pepper. Add flour and toss again until coated. Add the squash mixture to the baking dish, spreading evenly. Drizzle olive oil over the top and sprinkle with nutmeg. Bake uncovered until golden brown and the squash is tender (about 2 hours).
Recipe by Webicurean at http://blog.webicurean.com/2001/11/05/butternut-squash-gratin/