1. Heat the stock in a pan over a very low heat – have a ladle at the ready. Melt the butter and olive oil in a high-sided, non-stick frying pan. Add the onion and a large pinch of salt, then cook, stirring, for 5 mins until softened and fragrant but not colouring. Tip in the rice and coat in the oil and butter, cooking for a few mins until beginning to toast. Pour in the wine and cook, stirring, until it’s absorbed. Add the saffron and begin to add the stock, a ladle at a time, stirring continually. Add more stock as it’s absorbed. After 25-30 mins, all the stock should be absorbed and the rice should be creamy and al dente.