Cover tightly with plastic wrap and let it sit for 10 minutes. To serve, pack the sticky rice into custard cups or ramekins to shape, then invert each onto an individual serving plate. Serve with the mango slices. Kao neuw grains adhere to each other and are easily shaped into balls. The Laotians also share this custom.
Sticky rice is chewy and tastes buttery and nutty.
Cooked sticky rice is traditionally kept in, and served from, a beautiful bamboo woven basket, where it stays moist and warm for a long time. Because sticky rice is eaten only with the hands, a strict etiquette of washing before a meal is practiced. To eat, each person takes a handful of sticky rice from the container and breaks off a small amount, kneading it into a ball. This small ball of rice is then dipped into sauce or used to scoop up pieces of vegetable or meat. Thai people believe that sticky rice makes them mellow.