1. In a large nonstick saucepan, heat oil over medium heat. Add cauliflower and cook, stirring occasionally, until crisp-tender, about 5 minutes. Remove cauliflower to a bowl.

2. Add onion and curry powder to the saucepan and cook, stirring occasionally, until onion is softened, about 5 minutes. Add 2 cups of the broth and bring to a boil. Lower heat, cover, and simmer for 15 minutes. Let cool slightly.

3. Working in batches, puree the onion mixture in a blender or small food processor until smooth. Return the mixture to the saucepan.

4. Stir in the remaining 2 cups broth, pumpkin, salt, and cauliflower. Bring to a boil. Then lower heat, cover, and simmer until cauliflower is tender, about 10 minutes.