01 - Heat olive oil and 2 tablespoons butter in a large heavy saucepan over medium heat. Add chopped onion and cook until translucent, about 3 minutes.
02 - Stir in minced garlic and chopped sage leaves, sauté for 1 minute until aromatic.
03 - Add diced winter squash, season with salt and pepper, and cook for 5 minutes, stirring occasionally.
04 - Stir in Arborio rice and cook for 2 minutes, allowing grains to toast lightly.
05 - Pour in the dry white wine and simmer, stirring, until mostly absorbed.
06 - Add warm vegetable broth one ladleful at a time, stirring constantly and allowing each addition to absorb before adding the next. Continue until rice is creamy and al dente, about 20 to 25 minutes. You may not need all the broth.
07 - Adjust seasoning to taste. Stir in remaining 1 tablespoon butter, Parmesan cheese, and heavy cream, if using, until smooth and creamy.
08 - Remove from heat and let rest for 2 minutes. Serve garnished with extra sage and additional Parmesan if desired.