Spinach

European varieties of spinach are quite different from those used in China, although they make satisfactory substitutes for the Asian variety. Spinach is most commonly stir-fried, so frozen spinach is obviously unsuitable. Chinese water spinach (Ipomoea aquatica) is available in some greengrocers and in Chinese grocers. It has hollow stalks and delicate, pointed green leaves, lighter in colour than common spinach and with a milder taste. Cook when very fresh, preferably on the day it is bought.