Used in sweet and savoury dishes, the mung bean is an important feature of the cuisine of many Asian countries. What is it? A small nutritious legume with green skin, which is sometimes removed to reveal pale yellow flesh. How is it available? In East and Southeast Asian cuisines, mung beans are often sprouted (soya beans are also sprouted; mung bean sprouts are shorter and stubbier, and have a green - rather than yellow - 'head' hanging from one end). Dried mung beans are ground into flour to make small cakes and translucent 'noodles' such as fen si (also known as bean thread vermicelli, glass noodles or cellophane noodles) and fen pei (mung bean skins). Soaked mung beans are ground into a paste and mixed with sugar and oil to make a paste for steamed or baked pastries. What to look for? Mung bean sprouts should be white and crisp; after just a few days in the fridge they will start to turn brown and slimy. It isn't necessary to remove the heads of the sprouts but good chefs usually take them off because it makes the finished dish more refined. What else? Mung beans are high in protein so they're popular in vegetarian cuisine. How to use: dried fen si and fen pei need only a brief soaking in boiling water to soften them; if you boil the noodles for too long, they'll disintegrate. After draining the fen si or fen pei, add them to soups and stews; the noodles will soak up the flavours of whatever they're cooked with. Bean sprouts should be cooked quickly so they maintain their crisp texture. In Vietnamese cuisine, they're often added to soup noodles; the brief dip in the hot broth leaves them crunchy but removes the grassy taste of the raw sprouts. They're delicious when stir-fried. Heat oil in a wok, add a little salted fish and stir-fry briefly. Add the bean sprouts, some sliced fresh chilli and a sprinkling of salt and stir to mix the ingredients. Add some fish sauce or soy sauce, ground black pepper and a splash of water then stir-fry over a high heat for about two minutes. Mung beans - with or without the skins - make a nutritious dhal when cooked with onions, garlic and spices. Split, hulled mung beans can be fried then drained and sprinkled with salt, chilli powder and a squeeze of fresh lime juice, for a snack.