In a large saucepan over medium heat, melt the butter.
Sauté the shallot and garlic for 2 minutes.
Add the mushrooms, and stir.
Raise the heat to medium-high, and cook for about 10 minutes, or until the mushrooms start to brown.
Add the broth and bay leaves to the pan, and bring to a low boil.
Reduce the heat to low, and simmer for 15 minutes.
Add the cream from the top of the can of coconut milk, and season with salt and pepper.
Remove from the heat, and carefully purée with an immersion blender (or pour the soup into a blender in batches and purée, holding a clean dishtowel over the lid while blending to prevent potential eruptions).
Serve with a pinch of sliced scallions.