Sauté onions and garlic in a little butter or oil until translucent. Add ginger and thyme leaves (picked off the stem) and sauté for a further 1 minute. Pour in the stock and cook covered on a medium heat until the carrots have completely softened.
Once slightly cooled, pour the contents of the pot into a blender and purée until smooth. Season with salt and lots of fresh black pepper.
Return the soup to the pot and stir in the coconut milk. If the soup is too thick, loosen with a little stock or water to get the right consistency. Reheat gently before serving.