Rinse jasmine rice under cold water until the water runs clear.

In a medium saucepan, combine rice, coconut milk, water, salt, and sugar (if using).

Bring to a boil over medium heat, then reduce to low, cover, and simmer for 15–18 minutes until rice is tender and liquid is absorbed.

Remove from heat and let sit, covered, for 5 minutes. Fluff with a fork.

Serve warm or chilled with sliced mango on top. Garnish with sesame seeds or shredded coconut if desired.