Saute onion in saucepan with oil until soft. Add chopped garlic and cook until garlic just becomes fragrant. Add black beans, red beans and baked beans, (do not drain baked beans), and cook on low-medium flame. Meanwhile, drain tomatoes and slice the long way into halves or quarters. Add to beans. Add cilantro leaves. (You can use more or even no leaves depending on your flavor preference.) This dish can be served over rice or used as a filling for tacos or burritos. Enjoy!!!