Remove from oven and cool enough to handle. With a fork remove the flesh from the skin and set aside. In a large skillet heat the butter and olive oil over medium heat. Add the onion and garlic and sautee for a minute or two. Add the spaghetti squash and toss. Combine the Parmesan cheese and Italian seasoning and sprinkle over the spaghetti, toss until the spaghetti is well coated. Season with salt to taste. Serve.