In a large saucepan add the butter and olive oil then heat over a gentle moderate heat. Add the chicken, when white all over add the onion then cook until becoming transparent.
In a small saucepan add the chicken stock and thyme then bring to a simmer.
To the chicken add the rice and stir, when it has absorbed the butter and oil then add the wine. When the wine is absorbed add the chicken stock a ladle at a time, stirring after each ladle until absorbed.
When the rice is soft and the chicken stock gone stir in the pumpkin puree. Garnish with Parmesan.