Chop the leeks in half lengthways, then into even 3-4 inch pieces. Wash well to remove any dirt from in between the layers.

Melt a good knob of butter in a large frying pan over a medium-high heat. Sprinkle over the sugar and a good pinch of salt, then arrange the leeks, cut side down, in the base of the pan. Fry for 5-6 minutes, until the bottoms are golden brown, then add the wine, vegetable stock, lemon zest and thyme. Reduce the heat to low, cover the pan with a lid and simmer for 10-12 minutes, or until the leeks can be easily pierced through with a knife. Remove the lid from the pan and continue to cook for 2-3 minutes, to evaporate any remaining liquid.

Pierce open the burrata and spread into a small circle between two plates. Add the leeks on top, then drizzle over a generous spoonful of herb oil. Serve with lots of crusty bread.