1. Wash the rice well in several changes of cold water until the water is clear. Soak rice in the clean water for at least 1 hour. Drain and rinse well in the sieve. Place them in your rice cooker and add 2 cup water, then start the rice cooker.
Note : If you don't have a rice cooker, then combine the rice and water (3 cup) in the saucepan. Bring to a boil. Simmer the rice over low heat with a lid until water is absorbed.
2. While the rice is cooking, combine the coconut milk, sugar and salt in a small pan and bring it to a boil, stirring until the sugar dissolved. Reduce the heat to low and add diluted cornstarch. Remove from the heat. Pour the coconut milk sauce into a small bowl and chill to let it cool.
3. Cut mango into bite-size pieces. Set aside.
4. Place the sticky rice on a serving dish and arrange the mango side of the rice. Add the sauce. Sprinkle with sesame seeds.