In a large saucepan or medium stockpot over medium-high heat, add chicken stock, pumpkin puree, salt, nutmeg, cinnamon, and cayenne. Stir ingredients to combine and bring them to a boil, then reduce heat to low and keep the broth at just below a simmer.

In a separate stockpot or Dutch oven, heat oil and butter over medium-high heat until butter is melted. Add onion and cook for 2-3 minutes until translucent. Add garlic and cook for about another minute until fragrant.

Add rice to the pot with the onion and cook for 2-3 minutes, stirring constantly and ensuring all the rice is coated with oil and slightly toasted. Add about a half cup of the stock to the rice and cook until the stock is completely absorbed, stirring occasionally.

Repeat the process of adding and cooking the stock until about one cup of stock is left. Test the texture of your risotto to determine how much more stock you need to add. Cook until the rice is al dente, or still has a slight bite to it. I ended up with about a half cup of broth leftover. This process should take close to 45 minutes.

Once your rice has reached your desired consistency, remove the pot from the heat and stir in the parmesan cheese. Serve risotto immediately.