To cook canned black beans, start by pureeing one can of beans. Drain and rinse the other two cans. In a pan, sauté chopped onions and garlic for a few minutes until fragrant. Add the drained beans, pureed beans, chicken broth, chili powder, cumin, oregano, and any other seasonings you like. Stir everything together and cook for 10-15 minutes, stirring occasionally, until the beans are heated through and have absorbed the flavors. Serve as a side or use in your favorite recipes like tacos, salads, or soups.