In a large saucepan over medium-high heat, heat the oil. Add the onion and cauliflower and cook for 10 minutes, or until browned. Stir in curry powder, cumin and salt. Cook for 1 minute. Add 2 cups of the stock and bring to a boil. Reduce the heat to medium and cook covered for 8 minutes or until cauliflower is very tender.

Pour mixture into blender and blend until smooth. Return the mixture to the saucepan and add coconut milk and 2 cups stock. Stir to combine and cook for 5 minutes.