Richard Mabey began experimenting with cooking as soon as he was big enough to clamber to the cupboard where the powdered chocolate was kept. At scout camp he learned how to cook a Sussex Pond Pudding in a billy-can, and thirty years ago he permanently broadened the nation's palate with his guide to edible wild plants, Food For Free. His new book is a joyous exploration of local ingredients, broadening your horizons by travelling, vernacular...