Place cubed pumpkin, onion, garlic, grated ginger, salt, and pepper in a medium saucepan. Pour in the vegetable stock and water.
Bring to a boil over medium-high heat, turn down the heat to medium-low and simmer for 15-20 minutes or until pumpkin cubes are cooked.
Use an immersion blender or transfer the hot mixture into a food processor or a blender and process until all the pumpkin is pureed.
Transfer it back to the pan and boil it one last time. Taste for seasoning and add more if necessary.