How an old-fashioned root vegetable became my favourite preserve of the summer ... Some recipes arrive with months of planning. Others arrive in the hands of a neighbour carrying a rather extraordinary vegetable. When I was given mangelwurzels ahead of village Mangelwurzel celebrations, I'll admit I wasn't entirely sure where to begin. Most people know them as livestock feed, not something destined for toast or afternoon tea. But curiosity has always been my favourite ingre