Salt-baked celeriac with pickled celery, toasted hazelnut and truffle beurre blanc

Begin by roasting the celeriac. Preheat an oven to 180ºC/gas mark 4

Peel the large celeriac and wrap in foil with a drizzle of rapeseed oil and a good sprinkling of coarse salt. Bake in the oven for 1 hour or until cooked through. Leave to cool, then cut into 8 2cm-thick slices and use a ring cutter to create neat discs. Set aside until ready to reheat

While the first celeriac bakes, peel the second celeriac and cut into quarters. Take one quarter and dice into 7mm cubes, reserving any trim for the pureé. Make a pickle liquor by placing the sugar, vinegar and water in a pan with a pinch of salt and heating until the sugar dissolves. Leave to cool then add the celeriac cubes and leave to pickle for 1 hour

Roughly chop the remaining celeriac. Melt the butter in a large pan and add the chopped celeriac along with the trimmings from the pickle. Cook until the celeriac is caramelised and soft; this will take at least 20 minutes. Once soft, add the cream and warm through. Transfer to a blender and blitz to a smooth pureé. Taste and season with salt then transfer to a squeezy bottle

Peel and finely slice the celery, then add this to the pickling liquor with the celeriac cubes

To make the sauce, place 2 tablespoons of the pickling liquid into a small pan and reduce until almost entirely evaporated. Add the chilled butter piece by piece whilst continuously whisking until you have a thick glossy sauce. Season with salt and truffle oil to taste

To assemble the dish, reheat the discs of celeriac for a few minutes in a hot oven, then place them in the centre of each bowl or serving dish. Arrange the pickled celeriac and celery on top. Dot the pureé around and in the centre, then finish with the hazelnut pieces and rocket cress. Pour the warm sauce around the outside