In a large Dutch oven or soup pot, melt the butter over medium-high heat. Add the onion and sauté until soft, about 5 minutes. Add the garlic and sauté for another minute.
Add the carrots, apple, cilantro, jalapeño, salt, coriander and chicken broth. Bring to a boil them reduce to a steady simmer and cook, uncovered, until the vegetables are very soft, about 30-35 minutes.
Add coconut milk and puree the soup with a immersion blender or a regular blender** until silky smooth smooth. (For less heat, remove one half of the jalapeño before puréeing.)
If too thick, thin with a bit of chicken broth.
Taste and season with more salt, if needed, and a generous grind of black pepper.
Garnish with a few drops of creme fraiche, Greek yogurt or sour cream, thinned with a bit of milk.