Step 1

In a large, heavy-bottomed saucepan (preferably untreated cast iron or stainless steel), melt the butter over medium-low heat. Once the butter is melted and beginning to foam, add the sliced onions, a generous pinch of salt, and cover the pot with a lid.

Step 2

Uncovering to stir occasionally to prevent browning, cook the onions until they have softened and decreased in size by about half - about 20 minutes.

Step 3

Uncover the pot and, stirring frequently, cook the onions until they take on a uniform browned colour and have softened completely. If you notice the onions browning or burning around the edges, add a splash of water to the pot. Once the onions have reached a uniform deep amber colour, remove from the pot and allow to cool slightly.

Step 4

In a large mixing bowl, whisk together the ricotta, yoghurt, chives and Worcestershire sauce. Season with salt and pepper to taste.

Step 5

Fold in the caramelised onions and taste to adjust for seasoning. Transfer to an airtight container and refrigerate for at least one hour before serving.