Heat olive oil in medium nonstick saucepan over medium heat. Add bell pepper, onion, garlic, and oregano and saute mixture for about 5 minutes.
Add 2/3 cup of the beans to the pan. Using a potato masher, mash the beans briefly. Stir in the remaining beans, broth, oregano, and vinegar. Cover saucepan and simmer until the mixture thickens and the flavors blend, stirring occasionally, about 10 minutes.