Dried tangerine peel may have been born out of the unwillingness to waste anything in a time of poverty, but its distinctive flavour is essential to many dishes.
What is chun pei, exactly? Chun pei, as it's known in Cantonese, is made by air-drying the thin, easy-to-peel skin of different varieties of Citrus reticulata, such as tangerines, mandarins and satsumas. The flavour intensifies as the skin dries.
What to look for? Chun pei gets better (and more expensive) the longer it's been aged. You can usually tell by its colour - it gets darker with age.
What else? Chun pei is easy to make - peel the skin in largish pieces and rinse thoroughly. Thread onto a length of kitchen twine or dental floss, tying knots below and above each piece at approximately 1cm intervals so the air can circulate. Leave to hang for at least a month then store in an airtight container. It can be kept indefinitely.
Chun pei is believed to have a cooling effect, so it's helpful in alleviating sore throats, coughs and acne.
How to use? It's essential to sweet red bean soup. Rinse the red beans then place them in a pan with dried lotus seeds, a little salt, a few pieces of dried tangerine peel and enough water to cover the ingredients. Simmer until the red beans are tender and starting to break up. Add palm sugar to taste and simmer until it's dissolved, then serve hot.
Dried tangerine peel is often used with beef because its flavour balances the strong flavour of the meat - it's used in beef balls and the sweet, sticky dish known as tangerine beef. But it also goes surprisingly well with subtle, delicate fish. For steamed fish, soak the chun pei in warm water until soft then squeeze dry and finely julienne. Sprinkle the fish inside and out with salt then rinse and pat dry with paper towels. Make three slashes on each side of the fish all the way to the bone. Rub some cognac, brandy or rice wine into the flesh and cavity of the fish. Stuff with some of the tangerine peel, sliced spring onions and julienned ginger and scatter more of the same ingredients on top. Drizzle with soy sauce then steam until the fish is cooked. Meanwhile, heat some oil in a pan. As soon as the fish is ready, top it with a pile of fresh coriander leaves and finely julienned spring onions, then drizzle the hot oil over the aromatics to wilt them.