Mexico City chef Eduardo “Lalo” Garcia’s secret is to cook these beans very simply, for a very long time, until they’re super-soft, then to add his seasoning—a sofrito of onion, garlic, tomatoes, and dried chiles—and boil them for another half hour, simultaneously infusing them with flavor and concentrating their cooking liquid. These are some of the simplest and yet most complex beans I’ve ever tasted, let alone cooked. A straightforward pico de gallo adds a little freshness and crunch. Serve with tortillas.