01 - Preheat the oven to 425°F. Toss the cubed squash with olive oil, salt, and pepper. Spread evenly on a baking sheet and roast for 25 to 30 minutes, turning once, until golden and tender. Set aside.
02 - Heat the vegetable broth in a small saucepan over low heat and keep warm.
03 - In a large heavy-bottomed pot, melt 1 tablespoon butter with 1 tablespoon olive oil over medium heat. Add diced onion and cook 3 to 4 minutes until translucent. Stir in minced garlic and cook for 1 minute more.
04 - Add Arborio rice to the pot and stir continuously for 2 minutes until the grains are lightly toasted.
05 - Pour in the white wine and stir until fully absorbed by the rice.
06 - Add warm broth gradually, about 1/2 cup at a time, stirring frequently. Wait until liquid is nearly absorbed before adding more. Continue this process until rice is creamy and al dente, about 20 minutes, using as much broth as needed.
07 - Gently fold in roasted squash, Parmesan cheese, chopped sage, and remaining 1 tablespoon butter. Season with salt and freshly ground pepper to taste.
08 - Serve immediately, garnished with additional Parmesan and sage if desired.