The celeriac: Peel the celeriac, rub with lemon juice to avoid turning black, put through a fine vegetable mill. Put into an earthenware dish with the salt and the juice of 1/2 lemon and leave to sweat for 30 minutes to 1 hour. Drain, squeeze with your hands, put into a salad bowl. Add the sauce little by little, stirring to combine well. The quantity of sauce depends on the size of the celeriac, do not pour it in one go. The sauce: Make a mayonnaise with all the elements of the sauce. If too firm, you must thin it with 1 teaspoon water or milk. Leave to macerate for 30 minutes before serving sprinkled with chopped parsley (optional).
