Soak the rice in 1 cup water in a medium pot for 20 to 30 minutes. Do not drain the rice.

Add 1/2 cup more water, plus 1/2 can of the coconut milk, the salt, and 1 tablespoon of the brown sugar. Stir well. Bring to a gentle boil, then partially cover with a lid (leaving some room for steam to escape).

Reduce heat to medium-low and simmer 20 to 30 minutes, or until the coconut water has been absorbed by the rice. Turn off the heat but leave the pot on the burner with the lid on tight. Allow it to sit for 5 to 10 minutes.

To make the sauce, warm (do not boil) the remaining coconut milk over medium-low heat in a small saucepan (about 5 minutes). Add 3 tablespoons brown sugar, stirring to dissolve. Taste-test sauce for sweetness, adding more sugar if desired. (Note that it will not taste as sweet once added to the rice).

Prepare the mangoes by cutting them open and slicing each into bite-sized pieces.

Scoop some warm rice into each serving bowl, then drizzle lots of the sweet coconut sauce over the top. Arrange mango slices on the rice and finish with a drizzle of more sauce.