Halve the pumpkin, scrape out the seeds and cut the pumpkin into larger cubes. Also cut the onions into larger cubes.
Fry the onions in a saucepan with a little rapeseed oil and the cane sugar until they are brown. Be careful not to burn the sugar. Add the pumpkin and deglaze with a dash of white wine. Add the cream and fill up with enough water to cover everything. Season with salt and pepper and cook everything for about 15-20 minutes over medium heat, until the pumpkin is tender.
Peel the mango and cut into cubes and add the mango cubes to the pumpkin. Add the chopped coriander. After 2 - 3 minutes, puree the soup and season to taste.