1.In a heavy soup pot or Dutch oven over medium heat, heat oil. Add onion and garlic and cook until golden.
2.Meanwhile, halve, peel, and scrape out seeds of the pumpkin. Cut into chunks.
3.Add pumpkin chunks and broth to pot. Season with salt and pepper. Bring to a boil, uncovered, then reduce heat to a simmer. Simmer until pumpkin is fork-tender, about 30 minutes.
4.Remove pot from heat and, using an immersion blender, blend mixture until smooth. (Alternatively, let soup cool, then blend in a blender.) Stir in cream and season to taste.
5.To serve, ladle soup into bowls, add a swirl of cream, and garnish with pepper.