Preheat your oven to 200°C (400°F). Spread chopped pumpkin on a baking sheet, drizzle with a bit of olive oil, and roast for 20-25 minutes until tender and caramelized. Set aside.
While the pumpkin roasts, pour the vegetable broth into a saucepan and keep it warm over low heat.
In a large heavy-bottomed pot, heat olive oil over medium. Add diced onion and sauté until it becomes translucent and fragrant, about 5 minutes.
Add the minced garlic to the onions and cook for another 30 seconds until fragrant, making the kitchen smell inviting.
Stir in the arborio rice and toast it for 2 minutes, watching as the edges turn slightly translucent and the grains become glossy.
Pour in a ladle of warm broth and stir gently until the liquid is mostly absorbed by the rice. Repeat this process, adding broth a ladle at a time, stirring constantly, for about 20 minutes until the rice is creamy and just tender.
Gently fold in the roasted pumpkin chunks, allowing the rice to absorb their sweet, roasted flavor and vibrant orange color.
In a dry skillet, toast the sage leaves over medium heat until fragrant, about 30 seconds. Crumble or chop them finely.
Stir the toasted sage leaves into the risotto along with the grated Parmesan cheese and butter, mixing until everything is well combined and creamy.
Taste the risotto and adjust seasoning with salt and pepper as needed. Let it sit off heat for 2 minutes to settle.
Serve the risotto hot, garnished with extra sage leaves or Parmesan if desired, and enjoy the cozy, seasonal flavors.
