In a medium sized pot, melt the butter over medium-high heat and saute the onion, bell pepper, and garlic until soft about 10 to 15 minutes.
Pour the undrained beans, oregano, cumin, and water into the pot and stir well. Cook for another 6 minutes then add the vinegar, salt.
Puree 1 ladle of soup in a blender, then return to the pot. Stir well and cook for another 10 minutes. Ladle into bowls and garnish with green onions and cilantro. Enjoy!
Notes
ALERT!!!! This recipe is very high in sodium. Please balance with other recipes that are very low in sodium. Serves well with chopped avocado.
* Percent Daily Values are based on a 2000 calorie diet. Some amino acids levels are estimated, some product manufacturers do not supply amino acid values. The value source usda.gov.