01 - Heat vegetable broth in a medium saucepan and maintain at low heat.
02 - Melt 2 tablespoons of butter in a large skillet over medium heat. Add chopped onion and cook until translucent, about 3 minutes. Stir in garlic and cook for 1 minute before adding diced winter squash. Cook until squash begins to soften, approximately 5 minutes.
03 - Add Arborio rice and chopped sage to the skillet. Stir continuously for 2 minutes until rice is well coated and slightly translucent.
04 - Pour in the white wine and cook, stirring often, until the liquid is nearly evaporated.
05 - Add warm broth one ladleful at a time, stirring frequently. Allow each addition to be mostly absorbed before adding the next. Continue this process until rice is creamy and tender, and squash is cooked through, about 20 to 25 minutes.
06 - Remove from heat. Stir in remaining 1 tablespoon butter, Parmesan cheese, and heavy cream if using. Season with salt and freshly ground black pepper to taste.
07 - Immediately plate and garnish with extra Parmesan and fresh sage as desired.