Preheat oven to 400°F (200°C). Toss diced butternut squash with 1 tbsp olive oil, salt, and black pepper. Roast for 20-25 minutes until tender and slightly caramelized.

Heat vegetable broth in a saucepan and keep warm over low heat.

In a large pan, heat remaining olive oil and butter over medium heat. Add chopped onion and sauté until translucent, about 3-4 minutes. Add garlic and cook for another minute.

Add Arborio rice to the pan. Stir well to coat the grains with oil and toast slightly for 2 minutes.

Pour in white wine and stir until absorbed. Begin adding warm broth, one ladle at a time, stirring frequently. Wait until each addition is absorbed before adding the next.

After about 18-20 minutes, when rice is al dente and creamy, stir in roasted butternut squash, Parmesan, and chopped sage. Season with salt and pepper to taste.

Let risotto rest for 2 minutes before serving. Garnish with extra Parmesan and sage leaves if desired.