Rinse the leek thoroughly to remove any dirt, trim off the dark green leaves, and slice the white and light green parts into rings, discarding the root end.

Peel the onion, trim off the root end, and slice it into thin half-moons. Using the side of a spoon, peel the ginger, then chop it into small cubes.

In a large, heavy-bottomed pot, heat the olive oil over medium heat. Add the sliced leek, onion, and ginger, stirring to combine. Sauté for about 5 minutes until softened and fragrant.

Carefully cut the pumpkin in half, and if desired, peel off the skin. Peel the carrot and cut it into medium-sized chunks.

Add the pumpkin, pumpkin puree, and carrot to the pot, then pour in the vegetable broth. Ensure the broth covers most, if not all, of the vegetables. Bring the mixture to a boil, then reduce the heat to medium-low and let it simmer for about 20 minutes, or until the pumpkin and carrot are tender.

Blend the soup until smooth (see note below about blending). Return the blended soup to the pot and season with salt and pepper to taste. Stir in the heavy cream and gently heat until warmed through. Be careful not to let the soup boil after adding the cream, as it may cause the soup to split.