One of the wonderful things about spending time in tropical places when you grew up in temperate zones is the fruit. Oh, the fruit! Items that you once thought quite lovely at home - bananas, pineapples, mangoes - are revealed in their native habitat to be much more delicious than you had ever imagined.

This is revelation enough, but then there are all the brand new fruits that you had never even heard before: jackfruit, custard apples, rose apples... (Durian is another story, but let's not go there.) Many of these strange new fruits are not immediately recognizable as food, let alone luscious sweet fruit. And even when you've identified their food group, it's not intuitively obvious how to go about actually consuming them. It takes a kindly local to show you how to manage one, but once you figure it out, whole new fruit vistas open before you.

The pomelo (aka pommelo, pummelo, or shaddock (after a sea captain who first brought the seeds to Europe, apparently) - or, according to that quirky character Webster 1913, pompelmous, or forbidden fruit) was one such tropical discovery for me. True, it's easily recognized as a fruit - a citrus fruit, to be exact - but it's clearly a citrus fruit gone mad. It is akin to a grapefruit, but very much enlarged, ranging from the size of a cantaloupe to that of a large watermelon. A large pomelo can weigh up to 25 lbs (more than 10 kilos), and that's pretty gigantic. Even the small ones are hefty. The size is somewhat deceptive, for the rind is very thick, but even when you get the rind off, the edible bits inside are still of greater mass than a grapefruit. In Thai it's called som-oh, "giant orange".

I became a pomelo convert when the fruit lady at the end of my alley in Bangkok began to sell it, peeled and cut into quarters, when it came into season. I was instantly hooked. The membrane of the pomelo is very bitter and must be removed, but the flesh inside each section is very tasty, sweeter and less acidic than a grapefruit, and not as juicy, so it's easy to eat without making a mess. I ate a quarter every day, till it went out of season, after which I discovered the joys of jackfruit.

Turns out the pomelo is native to Thailand's neighbour to the south, Malaysia, and is thought to be the ancestor to the grapefruit. Like grapefruit, the peel of the pomelo can be pale or dark yellow or pinkish, and the flesh too can be yellow or pink or even dark red. They are grown throughout the tropical world and have been cultivated in southern China for thousands of years; someone told me they spent several months on a kibbutz in Israel picking pomelos. Pomelos are in season from around October through March, though because they store well, they can be found even after their season has passed.

Due to their peculiar characteristics, the usual method for sectioning citrus does not apply. Where normally you would be advised to cut off the rind and then cut each section out of its membrane, here you can easily free the delicious flesh from the membrane by hand. First, though, you've got to get through that thick rind. Take a sharp knife and score the rind into quarters; from there it's easy to pull off. Then cut the pomelo lengthwise into quarters and pull apart into individual sections. Cut the centre (thin) part of each each section off lengthwise, peel off the bitter membrane, discard any seeds, and voila! Delicious pomelo.

Pomelo is often used to make a delicious and refreshing salad in Thailand. One method is basically just a green mango salad using pomelo instead of green mangoes; this musters the usual suspects - chilis, coriander, peanuts - for a familiar Thai melange. But a more unusual and very delicious salad foregoes those old standbys and relies instead on coconut, caramelized onions and cashews for its flavour. Here's how to make it.

What you need:

What to do:

Liberate the pomelo sections (see above for directions) and break into bite-sized pieces.

Toast the coconut in small dry frying pan over medium heat till golden brown, stirring frequently. Watch it closely; it burns easily. Let cool.

Pour the oil into the frying pan and fry the onion over medium heat till very dark, almost burnt, stirring occasionally. Don't stir it too often, and don't stop before it's caramelized. Let cool.

Toss all ingredients together and serve with jasmine rice and other Thai dishes. Makes enough to serve four people as part of a Thai meal.