Cook the sweet potato ahead of time, by baking whole or steaming in chunks.
Puree everything except the pumpkin seeds, with 2 cups warm water in your blender on high for at least one minute, until slightly warmed. Add water as you need to get the consistency you want for your soup.
Serve topped with some pumpkin seeds.
Notes
Feel free to experiment with throwing other vegetables in your blender, depending on what appeals to you.