In a large, heavy-bottomed pan, heat some olive oil and add the rice. Add the remaining stock and cook for 12 minutes with the lid on until the stock has been absorbed, the rice is al dente, and has a lovely creamy consistency. Add the pumpkin puree into the risotto pan and stir together.
Finally, add freshly grated Parmesan and butter to the pan and stir well. Season with sea salt and pepper.
Serve the risotto on individual plates and spoon the Amarone Wine Sauce over top.
In a small bowl, mix together the water and flour. Gradually add the flour and water mixture to the pan, continually stirring, until the sauce has the desired consistency and flour is cooked (the sauce should be clear).