Quick Black Bean Chili

1 onion, chopped
2 garlic cloves, minced
1 green pepper, chopped
1, 28 oz. Can plum tomatoes, chopped
2 tsp. chili powder
pinch cayenne, or to taste
2 cans black beans

Combine all ingredients except the beans in a large pot, bring to a boil and simmer for 10 minutes. Stir in the beans and cook 5 minutes more. Freezes well.