n a sauté pan, heat the oil over medium heat until shimmering. Add the onions and cook until translucent but not colored, about 2 to 3 minutes. Add the grated ginger and sriracha, stir and continue to cook for another minutes or 2, until the ginger is fragrant. Take the pan off the heat and allow to cool to room temperature, about 10 minutes.

Meanwhile, take the can of coconut milk from the fridge – DO NOT SHAKE! (Chilling coconut milk overnight separates the fat from the liquid and allows the fat to rise to the top!) Carefully remove the top of the can and spoon out the top layer of solid coconut fat, about 1-inch from the top, and place in a small mixing bowl. Cover with plastic wrap and place back in the refrigerator. Pour the rest of the can of coconut milk into a blender along with the yogurt, water, brown sugar and mangoes to a blender. Add the onion mixture to the blender and blend on high for 2 to 3 minutes until completely smooth. Place the soup into an airtight container and chill for at least 8 hours.