Recommendation for Mexico City Norte
It is probably a 15+ minute but inexpensive taxi ride to Carnitas El Bajio's original location at Azcapotzalco. This location closes early - by 6:30 or so.
The Empanada de plátano rellena de frijol is a unique and delicious starter. If you want carnitas, you may want to order "solamente carne," unless you like offal and spare parts ; ). The specials, like a recent chile relleno with squash blossoms, are definitely worth trying, too.