Sweat onion in butter until translucent.· 5m
Toast rice 2 minutes, deglaze with wine until absorbed.· 4m
Ladle in hot stock with saffron, stirring, until rice is creamy and al dente.· 18m
Off heat, beat in cold butter and Parmigiano for the mantecatura.
Rest 1 minute, plate flat, tap to spread.