Prepare the sticky rice: Rinse the glutinous rice until water runs clear. Wash it and soak in water for about 4 hours or overnight. Drain the rice.
Cook the sticky rice: Put the soaked rice in a steamer basket lined with cheesecloth/ clean kitchen towel. Steam the rice over simmering water for 20 to 25 minutes or until soft and translucent.
Make the coconut sauce: Mix coconut milk, sugar and salt well in a pan. Place the mixture over low heat and stirring, cook until the sugar dissolves. Drizzle 1/4 cup coconut sauce when serving.
Mix rice with coconut sauce: And then transfer the rice in a mixing bowl. Pour in the rest of your coconut sauce with a very light stir through. The heat from the hot sticky rice will do the job for you! Allow it to sit for approximately 10 minutes to soak in the flavours.
Serve: Serve by placing a portion of sticky rice on each plate, top with sliced mangoes at the side and drizzle over reserved coconut sauce. Top with sesame seeds or mung beans, if using.