1 cup glutinous rice – rinsed until water runs mostly clear, soaked 4–6 hours, drained
14 ounces coconut milk (unsweetened, canned)
0.5 cup sugar
0.75 tsp salt
0.5 tsp rice flour
1 tbsp water
2 mangoes – ripe, peeled and sliced
1 tbsp sesame seeds – toasted
Instructions
Rinse the glutinous rice in several changes of cool water until it runs mostly clear. Cover with fresh water and soak 4–6 hours, then drain well.
Line a steamer basket with cheesecloth or a clean thin towel. Spread the drained rice in an even layer, cover, and steam over simmering water until tender-chewy and translucent on the outside, 20–25 minutes, flipping the rice once halfway through for even cooking.
While the rice steams, make the coconut mixture and sauce. In a small saucepan, combine the coconut milk, sugar, and salt. Warm over medium-low heat, stirring, until the sugar dissolves and the mixture is hot but not boiling, 3–4 minutes. Measure out 1 cup of this coconut mixture into a heatproof bowl for the rice. Return the remaining 3/4 cup to the saucepan; whisk the rice flour with the water to make a smooth slurry, then whisk it into the pan. Simmer gently, stirring, until slightly thickened and glossy, 1–2 minutes. Keep warm off the heat.
Transfer the hot steamed rice to a mixing bowl. Immediately pour the reserved 1 cup coconut mixture over the rice and fold gently until evenly coated. Cover and let stand until most of the liquid is absorbed and the grains are glossy and cohesive, 15–20 minutes.
Toast the sesame seeds in a small dry skillet over medium heat, stirring, until fragrant and golden, 2–3 minutes. Let cool.
Peel and slice the mangoes. Mound portions of the coconut sticky rice on plates, fan mango alongside, spoon some warm coconut sauce over the rice, and sprinkle with toasted sesame seeds. Serve warm or at room temperature.