Preheat your oven to 200°C (392°F). Spread the pumpkin cubes on a baking sheet and roast for 20-25 minutes until tender and slightly caramelized, filling your kitchen with a sweet, toasted aroma.
While the pumpkin roasts, pour the vegetable broth into a pot and warm it over low heat, keeping it just below simmer—this will be added gradually to the rice later.
In your large sauté pan, melt the butter over medium heat. Add the finely chopped onion and cook, stirring occasionally, until it turns translucent and fragrant—about 5 minutes.
Stir in the Arborio rice, letting it toast slightly for about 2 minutes until the edges turn translucent and you notice a nutty aroma filling the air.
Begin adding the warm broth one ladleful at a time, stirring constantly. Wait for each addition to be mostly absorbed before adding the next, allowing the rice to release its starch and become creamy.
Continue stirring and adding broth gradually, cooking for about 18-20 minutes until the rice is tender but still has a slight bite, and the mixture is creamy.
Gently fold in the roasted pumpkin pieces and sprinkle in the grated Parmesan cheese, stirring until everything is well combined and heated through. Season with salt and pepper to taste.
Remove the pan from heat, then stir in a small knob of butter or a splash of cream if desired for extra richness. Let the risotto rest for 2 minutes to settle.
Serve your pumpkin risotto hot, topped with additional Parmesan and a sprinkle of toasted pumpkin seeds or fresh herbs if you like for added texture and brightness.
