Peel the onion and cut it into large pieces. Warm a little olive oil in a Dutch oven over medium heat. Add the onion and cook gently until it begins to soften. Add the garlic and stir briefly.
Halve the pumpkin, scoop out the seeds, remove the peel, and cut the cleaned flesh into even cubes.
Add the pumpkin to the Dutch oven. Pour in a small amount of water, just enough to help the vegetables simmer without covering them completely. Stir in coriander, ginger, paprika, cumin, chipotle pepper, salt, and black pepper.
Cover and simmer gently for 15–20 minutes, stirring occasionally, until the pumpkin is fork-tender. Add a splash more water if needed.
Carefully blend the vegetables until completely smooth with an immersion blender. Stir in heavy cream to taste and adjust the seasoning.
Ladle the hot soup into bowls. Drizzle with a little extra cream and top with roasted pumpkin seeds. Finish with your favorite seasoning and, if desired, crumbled blue cheese or grated cheddar or Parmesan.
