Rinse the glutinous rice under cold water until the water runs clear, then soak it in cold water for at least 1 hour or overnight.

Drain the rice and place it in a heatproof bowl. Steam the rice in a steamer for 20-25 minutes until translucent and sticky.

In a saucepan, combine coconut milk, sugar, and salt over medium heat, stirring until sugar dissolves but do not boil.

If needed, mix cornstarch with cold water, then slowly add to the coconut sauce and stir until thickened.

Transfer the steamed rice to a bowl and mix in 1 cup of the coconut sauce. Allow to cool slightly.

Serve by mounding sticky rice on a plate with sliced mango, drizzling with the remaining coconut sauce and garnishing with sesame seeds.