@drmaryfraser
As the food shortages in Britain became more and more severe in early 1917, police wives, through the police weekly popular journal The Police Review and Parade Gossip were provided with vegetarian menus to help cut the escalating cost of food. These foods were said to be plentiful and cheap. However, they were not what humans would normally eat, as mangold-wurzel (the modern name is fodder beet) is normally cattle feed. Below is The Wive's Column which published these recipes.
It was surprising palatable although somewhat fibrous. It's certainly worth a try if you can get hold of one from a friendly local farmer.
@drmaryfraser