Heat oil in a large pot over medium heat. Add onion, green pepper and jalapeno pepper. Cook for 3 minutes until just tender but not browned. Add garlic and chili powder and cook 1 minute.
Add tomatoes, refried beans, pinto beans, black beans and bouillon powder. Mix well. Bring to a boil and then reduce heat to low. Cook for 20 minutes. If desired serve with some shredded cheese, corn tortillas or corn muffins.