Place the chopped pumpkin, zucchini, onions, and celery in a large soup pot and add the vegetable stock until at least half the vegetables are covered. Bring the broth to a boil then let simmer over low heat for 30 minutes.
Turn off the heat and let the soup cool to room temperature before puréeing vegetable and broth in a blender. Add 2 to 3 tablespoons of olive oil to the puréed mixture and return the soup to the pot and let simmer for 15 minutes before serving in individual soup bowls.
Top each serving with 1 tablespoon of olive oil and the pumpkin seeds, crumbled cheese, and ginger.