Heritage beetroot with burrata and pickled walnuts

Preheat an oven to 190°C/gas mark 5. Mix together the egg whites, table salt and rosemary to create a paste. Wash the beetroots and trim the roots off, then place in a pile on a baking tray. Spread the paste over the beetroots, ensuring there are no gaps and it is at least 2cm thick. Transfer to the oven and cook for 2 hours

Meanwhile, place a litre of water and 250g sugar into a pan with the walnut halves and slowly bring to the boil. Once boiling, drain the walnuts

Add the remaining 250ml of water and 250g of sugar to the pan and add the walnuts. Simmer for 1 hour, ensuring they are always submerged

Make the pickled walnut purée by adding the sugar to a dry pan over a medium heat. Cook until the sugar turns to a golden-brown caramel, then add the rest of the ingredients. Stir and continue to cook until the apple has brown down and everything is well combined, then blitz in a blender until smooth. Transfer to a squeezy bottle until ready to plate

Once the beetroots are cooked, leave to cool slightly then break open the salt crust. Peel the beetroot, ensuring any salt crust is brushed off, then cut into wedges and set aside

Once the walnuts have been simmering for 1 hour, drain and leave to cool. Preheat a deep pan of oil or deep-fat fryer to 150°C

Deep-fry the boiled walnuts for 4 minutes until crispy, then drain on kitchen paper

To serve, cut the burrata balls in half and place in the centre of 4 plates. Arrange the beetroot wedges around the cheese, then season everything generously with extra virgin olive oil, salt and pepper. Scatter the pickled walnuts and deep-fried walnuts around the burrata, then finish with dots of the pickled walnut purée. Garnish with sprigs of watercress