When cooked, bamboo pith looks like the plastic netting placed over fruit to protect it from bruising. What is it? Bamboo pith, also known as bamboo mushroom, is a hollow fungi that grows on bamboo plants. It's mostly grown in Yunnan province, home to many other varieties of mushroom. Bamboo pith is about 6cm long and the colour ranges from off-white to pale brown. When dried, it resembles miniature loofah sponges. What to look for: off-white bamboo pith is usually more expensive than the darker specimens. Examine the product carefully for the presence of bugs. How it is available? Dried, usually in small bundles tied with string. It should be thoroughly rinsed before use in case it contains sand. The product can be found fresh in Yunnan. What else? Because of its lacy fibres, bamboo pith absorbs flavours like a sponge. It has a tender, slightly crunchy texture. As with other dried mushrooms, bamboo pith should be soaked before it's cooked. How to use: soak bamboo pith, dried shiitake and cloud-ear mushrooms until completely rehydrated then braise them with straw mushrooms and enoki. Flavour with soy sauce, oyster sauce, rice wine and white pepper; if necessary thicken the sauce with a little cornstarch mixed with water. The hollow centre of bamboo pith is perfect for stuffing. Use vegetables and meats cut slightly longer than the bamboo pith: thin asparagus spears, enoki mushrooms, slivered Jinhua ham, julienned carrots and thinly sliced pork that's been marinated with soy sauce, rice wine and a little sugar. Steam the bundles until the meat and vegetables are tender. Make a sauce by simmering unsalted chicken broth with a little oyster sauce, soy sauce, rice wine, sesame oil and enough cornstarch to thicken slightly. Pour this over the bamboo pith bundles and serve immediately. Bamboo pith can also be stuffed with fresh fish paste (available from fish vendors at wet markets) to which finely chopped dried tangerine peel, grated fresh ginger and minced spring onions have been added. Use a pastry tube to pipe the filling into the bamboo pith (this isn't easy) then steam until cooked. Serve with a dipping sauce of soy sauce mixed with freshly chopped chillies.