Though fresh ingredients are available from any market stall, there are very few opportunities to cook for yourself in China, and most of the time eating out is much more convenient and interesting. The principles of Chinese cooking are based on a desire for a healthy harmony between the qualities of different ingredients. For the Chinese, this extends right down to considering the yin and yang attributes of various dishes - for instance, whether food is "moist" or "dry" - but can also be appreciated in the use of ingredients with contrasting textures and colour, designed to please the eye as well as the palate. Recipes and ingredients themselves, however, are generally a response to more direct requirements. The chronic poverty of China's population is reflected in the generally scant quantity of meat used, while the need to preserve precious stocks of firewood led to the invention of quick cooking techniques, such as slicing ingredients into tiny shreds and stir-frying them. The reliance on eating whatever was immediately to hand also saw a readiness to experiment with anything edible; so, though you'd hardly come across them every day, items such as bear's paw, shark's fin, fish lips and even jellyfish all appear in Chinese cuisine.