Durians look like overgrown medieval weapons. People certainly have been killed by them - not in fierce battles, though, but by being struck by the hard, heavy fruit falling from a tree. Some people also claim the powerful odour they emit is deadly.
What are they? Large, yellow-ish green fruit with a spiky shell and extremely pungent scent. The spikes are so hard durians need to be handled with gloves. Inside the shell are large lobes of fruit with a dense, creamy texture and sweet, complex flavour that's reminiscent of garlic and rotting garbage (but in a good way). The flesh of each lobe surrounds a large, hard seed that can be cooked and eaten, although it might make the eater emit noxious, embarrassing fumes (this isn't from personal experience).
Where are they grown? Most of the durians sold in Hong Kong are from Thailand, but they're also grown in Malaysia, the Philippines, Indonesia and Vietnam. Although they all look similar, there are many different wild and cultivated varieties.
What to look for? A good fruit vendor. He or she will be more adept than you at choosing a ripe durian. If you must pick one yourself, handle it gingerly and inspect it to make sure there are no insect holes. Then give it a shake: you should feel the fruit inside moving around slightly but not too much (which would mean it's over-ripe). If you're buying the flesh on styrofoam trays from the supermarket, make sure it gives a little when you press it.
What else? Durian is known as the king of fruits. It's in the same family as the lychee, longan, rambutan and mangosteen. It is thought to heat the body and it is believed eating too much will make you cough and break out in pimples. To counteract the 'heat', you should drink salted water out of the durian shell, and/or eat mangosteens, which are considered cooling. The fruit is fattening and is said to be an aphrodisiac by some.
How to prepare? Most durian lovers would say the best way to enjoy it is straight from the shell. Freezing the flesh tones down its smell. For a simple durian ice cream, eat it while it's still semi-frozen. The flesh can also be mashed and mixed with whipped cream to use as a filling for crepes, cakes and tarts.