Over the next three years Grigson returned to producing books dealing with key categories of food: two booklets, "Cooking Carrots " and "Cooking Spinach" were published in 1975, as was "The Mushroom Feast". The last of these was described by "Kirkus Reviews" as "A beautiful collection of recipes and culinary lore" the reviewer for "The Observer" noted that "Grigson gives you more than recipes. She takes you down the byways of folklore and literature". Grigson described it as "the record of one family's pursuit of mushrooms, both wild and cultivated, over the last twenty years". Unlike many of her other books it owed little to her previously published articles, but drew on her family's experiences as mushroom enthusiasts. The idea of writing a book on fungi came to her after a friend in Trôo introduced the Grigsons to mushroom gathering. For him, as for other locals, "mushroom-hunting was part of the waste-nothing philosophy he had inherited from his farming peasant ancestors. ... mushrooms have long been accepted by chefs of the high cooking tradition in France: there is no question of allowing them to go to waste as we do so unregardingly". She had gradually concluded that few available books did justice to mushrooms and other fungi: "Most cookery books—always excepting "Plats du Jour" by Patience Gray and Primrose Boyd—are useless". Reviewing the first edition, Skeffington Ardron wrote in "The Guardian" that choosing between the many recipes "will drive you wild, for there is here such a magnificent collection" ranging from simple economical dishes to "the extravagant, impossible, ridiculous "Poulard Derbe" with its champagne, foie gras and truffles".