Salt-baked celeriac

Preheat the oven to 160°C/gas mark 3

To make the crust, combine the flour, salt, egg whites and water and mix thoroughly to form a paste. Wash the celeriac thoroughly, trim off any roots and cut off a small amount of the base of each so they can sit flat on the baking tray

Add two mounds of the salt crust to a sturdy baking tray and spread out slightly to make bases for the celeriac, ensuring the bases are slightly wider than the bottom of each celeriac. Place the celeriac on top and use the remaining salt crust to completely cover each celeriac. Make sure there aren't any gaps or holes in the crust

After 3 hours, or once the pastry forms a hard, golden crust around the celeriac, remove from the oven. Use a strong metal spatula to loosen the base of each of the celeriac before lifting it from the baking tray

Use the heel of a knife to make small cracks around the top of the crust, until you can gently lift off the newly formed lid. Serve whole at the table with a spoon to scoop out the celeriac