Wash rice a few times in cold water. Place into a bowl and cover with water. Allow to soak for six hours or overnight.
Lay a cheese cloth down on a bamboo steamer basket. Drain rice and lay on top of the cloth. Place steamed basket atop a fry pan filled with simmering water. Make sure the water doesn’t touch the bottom of the basket.
Steam for 30 minutes or until rice is tender.
Meanwhile, warm coconut milk over a low heat in a small pot on the stove, making sure not to boil. Add salt and stir to dissolve. Pour out half the coconut milk - this will be your sauce later. To the remaining coconut milk, stir in sugar. Set aside.
Once rice is cooked, transfer to a heatproof bowl. Add the sweetened coconut milk mixture and stir through. Cover at set aside for 30 minutes to rest.
Slice mango cheeks into one centimetre pieces. To serve, divide rice on to four plates with a sliced mango cheek on the side. Drizzle with salted coconut milk sauce and sprinkle with toasted sesame seeds.