Sauté the onion: In a large pot, melt the butter over medium heat. Add the diced onion and cook until softened, about 5 minutes.

Add pumpkin and broth: Stir in the pumpkin puree and chicken broth. Bring the mixture to a boil, then reduce the heat and let it simmer for 15 minutes.

Blend the soup: Use an immersion blender to puree the soup until smooth.

Add coconut milk and seasoning: Stir in the coconut milk and ground nutmeg. Cook on low heat until warmed through. Season with salt and pepper to taste.

Serve and garnish: Ladle the soup into bowls and garnish with fresh sage leaves for an added touch of flavor and aroma.