Pour the vegetable broth into a pot and bring to a gentle simmer, keeping it warm throughout the process.
Finely chop the small onion, preparing it for sautéing.
Heat the olive oil and butter in a large heavy-bottomed pan over medium heat until the butter melts and begins to bubble gently.
Add the chopped onion to the pan and sauté until translucent and fragrant, about 5 minutes, stirring frequently.
Stir in the Arborio rice, cooking for about 2 minutes until the edges turn slightly translucent and it starts to toast lightly.
Pour in the white wine and stir until it has mostly evaporated, releasing a fragrant aroma.
Begin adding the warm broth one ladleful at a time, stirring constantly and waiting until most of the liquid is absorbed before adding the next ladle.
Continue this process, stirring regularly, for about 20-25 minutes, until the rice is tender but still slightly al dente and the mixture is creamy.
Stir in the pumpkin puree and a pinch of freshly grated nutmeg, cooking for another 5 minutes until heated through and fragrant.
Add the cream (if using) and grated Parmesan cheese, stirring until the cheese melts and the risotto becomes silky and rich.
Taste and adjust the seasoning with salt and pepper as needed. Let the risotto rest for a couple of minutes off the heat.
Spoon the pumpkin risotto into bowls, garnish with extra Parmesan and a drizzle of olive oil for a warm, inviting presentation.
