Melt half of the butter in a large, deep-frying pan (or stockpot) over medium heat. Add the olive oil and onion and cook without browning for 2 minutes or until soft. Add the pumpkin and sage. Cook, stirring, for 5 minutes, then season with sea salt to taste.
Stir in the rice and after 2 minutes, pour in the wine. Cook, stirring, until all the liquid has been absorbed.
Add a ladleful of the hot stock, stirring constantly. When the stock has been absorbed, stir in another ladleful. Continue to add ladlefuls of stock, stirring and allowing each ladleful to be absorbed before adding the next until the rice is ‘al dente’ (approximately 15 minutes).
Remove the frying pan (or stockpot) from the heat. Stir in the remaining butter and scamorza affumicata. Top the risotto of pumpkin, sage and scamorza affumicata (smoked mozzarella) with grated Parmigiano Reggiano. Serve immediately – buon appetito.