Coat bottom of a large stockpot with cooking spray. Add onion, garlic, and chopped bell peppers to the stockpot and sauté over medium heat, until vegetables are tender (about 5 minutes).

Place one can of beans in blender; add sautéed onion/pepper mixture and mix. Cover and blend on high until smooth, about 30 seconds. Pour mixture back into stockpot.

Stir second can of can of beans (do not puree first), tomatoes and green chilies, and chicken broth into stockpot. Bring to a boil, lower heat to medium and simmer for 20 minutes. Yields about 6 1 1/2 cups of soup per serving.