Flummery was a mainstay of the Nineteenth Century Radnorians diet. It should not be confused with the arty-farty fruit puddings that masquerade under the name today. Here's a recipe provided by Alfred Wallace, the chap who came up with Darwin's theory of natural selection and who worked a good deal in Radnorshire:
"Another delicacy we first became acquainted with here was the true Welsh flummery, called here sucan blawd (steeped meal), in other places Llumruwd (sour sediment), whence our English word "flummery." It is formed of the husks of the oatmeal roughly sifted out, soaked in water till it becomes sour, then strained and boiled, when it forms a pale brown sub-gelatinous mass, usually eaten with abundance of new milk. It is a very delicious and very nourishing food, and frequently forms the supper in farmhouses. Most people get very fond of it, and there is no dish known to English cookery that is at all like it."