Take one chestnut from the pack and set aside. Tip the rest of the chestnuts into a blender or smoothie maker with the lemon juice, garlic, oil and a little freshly boiled water from the kettle. Season. Blitz to a smooth purée, then spoon into a bowl or spread over four plates.

Finely grate over the reserved chestnut, then serve with pitta crisps and vegetable crudités.