Dice the pumpkin. Then chop the onion, put it in a pan with a little bit of oil and let it brown; add the pumpkin and let it brown. Cook it for about 20 minutes, adding the stock with a ladle: then add the rice and add the stock from time to time, until the rice is fully cooked. Once ready, remove the rice from the heat and mix with butter and parmesan. Garnish the dish by drawing a cobweb with the balsamic vinegar glaze.