Start by peeling your pumpkin and cutting it into evenly sized cubes, about one inch each. Even sizing matters here because it helps everything cook at the same rate. I like using a butternut squash-style pumpkin since the skin peels off easily with a vegetable peeler.
In your pot, heat the olive oil or butter over medium heat and add the sliced onion along with the whole garlic cloves. Cook for about five minutes until the onion turns soft and translucent, not browned. This step builds the flavor foundation for the whole soup.
Add your pumpkin cubes, stock, and water into the pot with the softened onion and garlic. Bring it to a gentle boil, then reduce the heat to a simmer. Let it cook for around 15 minutes, or until the pumpkin is completely fork-tender.
Carefully transfer the soup to a blender, or use an immersion blender directly in the pot. Blend until the mixture is completely smooth with no lumps. This is the step that turns a basic vegetable soup into that irresistibly creamy pumpkin soup texture.
Pour the soup back into the pot if you used a blender, then stir in your cream over low heat. Season generously with salt and pepper, tasting as you go. Warm it through gently, but don't let it boil once the cream is added.
Ladle the hot soup into bowls and add your favorite toppings right away while it's steaming. I always keep some crusty bread on the side because it's simply unmissable with this soup. This is the moment all that simmering pays off.