In a large saucepan, over medium heat, add the oil. When the oil is hot, add the sausage and brown for 2 minutes.
Add the onions and peppers. Season with salt and pepper.
Sauté for 3 to 4 minutes or until the vegetables are wilted. Stir in the garlic and black beans.
Sauté for 1 minute. Add the stock and bring to a boil, reduce the heat to medium-low and simmer until the beans are creamy and tender, about 2 1/2 hours, stirring occasionally.
Stir in the butter and reseason wit salt and pepper.
Makes: 12