Melt 50 g of butter, then add the chopped onion. Pour the Carnaroli rice and leave it to toast for a few minutes: as soon as it becomes sheer, add 250 ml of Vino Nobile di Montepulciano DOCG. Once dried, add some chicken stock and keep mixing until it dries. Now, you can add the remaining Vino Nobile di Montepulciano DOCG. When it is dried too, keep adding the chicken stock until it is finished and totally dried, always mixing. At the end of cooking, turn off the heat and stir in the risotto by adding the Parmigiano Reggiano DOP and the remaining butter. Serve hot.