In medium pan over medium heat, warm oil and add onions. Cover pan, sweating onions until tender and translucent, 5–7 minutes.

Once tender, stir in ginger and curry paste, cooking until fragrant, 1–2 minutes. Remove from heat and cool to room temperature.

While onions are cooling, combine yogurt, brown sugar and coconut milk in bowl; set aside.

Place half quantity of onion mixture, yogurt mixture and half of mangos into a blender and blend until smooth. Pour soup into mixing bowl or lidded container. Repeat process with remaining ingredients and combine.

Taste and adjust seasoning with additional curry paste for heat or additional yogurt to cool.

Refrigerate for at least two hours or overnight before serving, allowing flavors to develop.

Serve chilled with whipped coconut, a dollop of yogurt, or a drizzle of chili oil.