Winter squash risotto with sage and parmesan

This one takes some time and effort, but is worth it in the end. Makes plenty for 4 people as a main course.

2 1/2 lbs winter squash, halved, seeds and strings removed with a spoon and reserved
3 tbls unsalted butter, 1 tbls melted
Salt
1 quart vegetable broth
1 tbls olive oil
1 medium onion, finely chopped
2 medium garlic cloves, minced
1 1/2 cups arborio rice
3/4 cup dry white wine
3/4 cup freshly grated parmesan cheese
1 tbls minced fresh sage leaves
freshly grated nutmeg

1. Move oven rack to the middle position and heat the oven to 450 degrees. Place the squash, flesh side up, on a rimmed baking sheet. Brush the squash with melted butter (I sometimes do this with olive oil) and sprinkle with salt. Bake until tender, 45 minutes. Remove the baking sheet from the oven and set the squash aside. When cool, use a spoon to scrape the flesh from the skins into a bowl. Discard the skins and lightly mash the flesh with the spoon until smooth. (You should have 1 1/2 to 1 3/4 cups).

2. Meanwhile, place the squash scrapings (the seeds and strings) in a medium saucepan. Add the vegetable broth and 1/2 tsp salt and bring to a boil over high heat. Reduce heat and cover, and simmer until the flavor has been extracted, about 20 minutes. Strain the mixture through a fine-mesh strainer into a large measuring cup, pressing the squash scraping to extract as much liquid as possible. (Do not wash the saucepan). Return the squash broth to the empty saucepan along with enough water to make 6 cups. (You'll probably have to add about 2 cups of water). Bring the squash broth to a simmer. Turn off the heat and cover to keep the broth warm.

3. Heat the remaining tbls of butter and the oil in a heavy-bottomed medium saucepan over medium heat. When the foaming subsides, add the onion and cook, stirring occasionally, until softened, about 4 minutes. Add the garlic and cook until fragrant, about 1 minute.

4. Stirring constantly with a wooden spoon, add the rice and cook for 1 minute. Add teh wine and cook, stirring often, until the wine nearly evaporates, about 2 minutes. Add 1 cup of the hot broth and cook, stirring frequently, until the rice absorbs the liquid. Continue adding the broth in 3/4 cup increments and stirring often until the rice is creamy (not soupy) and soft, but still a bit al dente, about 25 minutes. (You probably won't use all of the broth. )

5. Remove the saucepan from the heat and vigorously stir in the roasted squash, cheese, sage, and remaining 1 tbls of butter. Adjust the seasonings adding salt and nutmeg to taste. Serve and pass grated cheese at the table.