In a medium pot over medium-high heat, melt the butter. Add the onions and salt. Cook, stirring, until the onions are soft, about 3 minutes. Add the garlic and cook, stirring, another minute or so until the mixture is very fragrant.

Add the chilies and broth (3 cups for a thicker soup, 4 cups for a thinner soup) to the pot and bring to a boil. Reduce heat to maintain a steady simmer and cook until vegetables are extremely soft and flavors have blended, about 15 minutes.

Blend until very smooth in blender or food processor (about 2 minutes).

Return the mixture to the pot and stir in cream. Gently heat until the soup is heated through. Add more salt to taste, if you like. Enjoy.