Melt in a soup pot over medium heat:
Add and cook, stirring, until tender but not browned, about 6 minutes:
Stir in:
Bring to a boil, then reduce the heat, partially cover, and simmer until the carrots are tender, 15 to 20 minutes. Puree the soup with an immersion blender (or in batches in a food processor or regular blender) until smooth. Return to the pot and stir in:
Heat through, but do not boil. Garnish with: