Horseradish is native to the Mediterranean, although it has been growing wild in Britain for centuries, as it has in the rest of Europe and Scandinavia. It grows virtually anywhere and we used to take a shovel and dig a root up when we needed it in Wales. You don’t have to go to those extremes, and it’s probably illegal to do so now; you can buy it in powdered or grated form or in ready-made sauces, including one with Roquefort cheese. It is related to the
wallflower family and to mustard and Brassica, such as
broccoli. It contains the same constituent (sinigrin) as
black mustard seed, and is now used as a condiment in much the same way as mustard is. The French call horseradish
Moutarde des Allemandes, or mustard of the Germans, as it was these people who first used it as a condiment in Europe.