Cut the pumpkin flesh into large pieces. Peel and finely chop the ginger. Squeeze the garlic cloves. Finely dice the onions. Heat the oil in a saucepan, sweat the prepared ingredients in it over medium heat while stirring for 5 minutes.
Top up with vegetable stock and bring to the boil. Boil the soup for 20 minutes, purée finely and strain through a sieve. Season with salt, pepper, some chili powder and lime juice.
Toast the sesame seeds in a pan without fat. Sprinkle the soup with the sesame seeds and parsley.