Wash the sweet pumpkin thoroughly, remove the seeds, and steam it with the skin on.
Let the steamed pumpkin cool, scoop out the flesh, and mash it finely.
Add sugar and salt to the mashed pumpkin and mix well.
Whip the heavy cream until lightly thickened, then fold it into the pumpkin mixture.
Transfer to a bowl and chill in the refrigerator for at least 1 hour until set.
Serve the finished sweet pumpkin mousse in a dish.