Thai sticky rice is a special kind of rice that grows in the north of the country. When cooked, the grains stick together in a soft, chewy lump instead of staying separate like normal rice. For pudding, the cook adds warm coconut milk, a pinch of salt and a little sugar.
The mango has to be just right. In Thailand, the favourite kind is called nam dok mai, which means 'flower water'. They are smooth, yellow, with no strings, and so juicy that you almost don't need a fork. The mango goes next to the rice (not on top), and you take a bit of both in the same spoonful.
The dish is at its very best between March and June, when mangoes are properly ripe across Thailand. You can find it on every street corner during those months, often sold by sellers with a small ice box of rice in one hand and a basket of mangoes in the other.
Mango sticky rice has now travelled the world. It is on Thai restaurant menus in Tokyo, London, Sydney and New York. But many Thai cooks will tell you the version you eat in Thailand - with a ripe mango picked that morning - is still the best you'll ever have.