on friday, we had steamed mussels in a pretty conventional liquid--wine, fresh herbs, shallots, garlic, chopped tomatoes, and cream. we had about 3 cups of liquid left over so i saved it. for our football lunch saturday, i added a cup of milk to the leftover broth and used it to make the cheese sauce for mac and cheese. it was terrific.
i'll plan this sequence on purpose another time. maybe soup another day.