Caribbean Carrot-Ginger Soup

Heat butter and oil in a large saucepan over medium heat. Add onion; cook until translucent, 5 to 6 minutes. Add carrots and ginger; cook for 1 to 2 minutes more. Stir in broth and salt. Bring to a boil. Reduce heat; simmer, covered, until carrots are very tender, 20 to 30 minutes.

Puree soup with an immersion blender until smooth and creamy, or let cool slightly and blend in a blender, working in batches as needed. Return to heat and add more broth as needed for desired consistency; soup should be thick. Season with pepper and additional salt if needed.

Ladle soup into 4 bowls. Swirl 2 tablespoons coconut milk into each bowl.