Sort and wash lentils.
Add lentils and vegetable broth to a large pot, then place over medium heat. Bring it to a boil, cover the pot, then reduce heat to simmer for 20 minutes.
Add onion, garlic, celery, green onion, thyme, carrot, potato, basil, oregano, garlic powder, onion powder, cayenne pepper, and pumpkin puree, and cook for 10 minutes or until vegetables are tender, then season with salt to taste.
Now, you have to decide the texture of the soup. For example, you may leave it chunky if you want it to be more like a pumpkin lentil stew. Or, you can use an immersion blender to puree all or some of the soup slightly. Put another way, add 50% of the soup mixture to a blender or food processor, put it back to the pot with the other half, and stir well.
Finally, taste it and adjust the seasoning if required. Serve warm.