"Our family loves black beans, so I am always looking for new ways to cook them. I came up with this recipe after trying to find a way to use up some leftover fresh sage. My partner absolutely loves the result!"
Heat oil in a saucepan over medium high heat. Fry onion and garlic in hot oil until onion is transparent, 5 to 7 minutes.
Stir black beans, chicken stock, and sage leaves with the onion mixture; add just enough water to the saucepan to cover the beans completely. Bring the mixture to a boil, reduce heat to medium-low, and simmer until the beans are soft, about 15 minutes. Remove and discard sage leaves.
Pour soup into a blender no more than half full. Cover and hold lid in place; pulse a few times before leaving on to blend. Puree in batches until smooth. Return soup to saucepan and place over low heat.
Stir 1/4 cup grated Parmesan cheese and butter into the soup; cook and stir until melted, 2 to 3 minutes. Remove saucepan from heat and stir cream into the soup until smooth. Garnish with green onion and grated Parmesan cheese.