1 Caramelise onions
Preheat the oven to 200°C/180°C fan. Peel and slice the onions finely. Heat a drizzle of oil in a pan over a high heat. Once hot, add the butter and the onions. Fry the onions with a pinch of salt for 3-4 min until lightly browned. Reduce the heat to low and cook, over a very low heat, stirring occasionally, for 10 min further or until the onions have fully softened and caramelised. Don't rush this step!