These deep-fried balls with irresistible Middle Eastern flavor have become street-corner staples in large American cities, where thousands of them are sold from pushcarts daily. But they're also easy to prepare at home. You can make them with chickpeas, with fava beans (as they do in Egypt), or with a combination of the two. We like them with chickpeas alone. Makes 16 falafel, enough for 4 sandwiches or 4 first-course servings.