01 - Preheat the oven to 400°F. Toss diced squash with 1 tablespoon olive oil, salt, and pepper. Spread evenly on baking sheet and roast for 20 to 25 minutes, turning once, until tender and golden. Set aside.
02 - Heat 2 tablespoons butter and remaining 1 tablespoon olive oil in a large sauté pan or Dutch oven over medium heat. Fry sage leaves in a single layer for 1 to 2 minutes until crisp. Remove with slotted spoon and drain on paper towels.
03 - In the same pan, add chopped onion and cook over medium heat for 4 to 5 minutes until softened and translucent. Add minced garlic and cook for an additional minute.
04 - Stir in Arborio rice and cook for 2 minutes until grains are glossy and fully coated with fat.
05 - Add a ladle of warm vegetable stock, stirring continuously until absorbed. Repeat by adding stock one ladle at a time, stirring frequently and allowing absorption before the next addition. Continue for 18 to 20 minutes until rice is creamy and al dente.
06 - Gently fold roasted butternut squash into risotto. Stir in remaining 2 tablespoons butter and grated Parmesan cheese. Season with salt and freshly ground black pepper to taste.
07 - Plate immediately, topping each serving with crispy sage leaves and extra Parmesan if desired.