In a medium saucepan, melt 2 tablespoons of the butter. Add the chopped onion, carrot, celery, and garlic; cover and cook over moderately high heat, stirring occasionally, until the vegetables are just beginning to brown, about 5 minutes.

Sprinkle the flour over the vegetables and stir over low heat for 1 minute, or until the flour is fully incorporated.

Add the chicken stock, tomatoes, bell peppers, tomato paste, and maple syrup and bring to a boil. Cover partially and cook the soup over moderate heat, stirring occasionally, until the vegetables are tender, 15 minutes.

Use an immersion blender to puree the soup until smooth (or as smooth as you like your soup!)

Add the coconut milk, and cook until the soup is just heated through. Season the soup with salt and pepper and swirl in the remaining 2 tablespoons of butter. (If you like completely smooth soup you can also pour it through a fine mesh sieve at this point), Ladle the soup into bowls, garnish with croutons or grilled cheese, and serve.