leach has studied food, eating, cooking, associated equipment and paraphernalia in new zealand. her interests range from prehistoric horticulture and the evolution of human diet to the history of cooking, the origins of recipes as well as the development of kitchens and batteries de cuisine in the twentieth century. her extensive collection of cookery books, especially community cookbooks, has provided a significant resource for colleagues' investigations that compensated for the incompleteness of that of the national library of new zealand. reviewing leach's most recent book "kitchens", barbara santich observed that "new zealanders are indeed fortunate to have helen leach as guide, guardian and safe-keeper of their gastronomic past", noting too that the work was illustrated with images of artefacts from leach's own personal collection.