Season the meat with salt and pepper. Heat the oil in a heavy large pot over moderately high heat until hot but not smoking. Cook the beef in 2 or 3 batches, turning occasionally, until browned, 6-8 minutes per batch.
Add the chiles and continue to simmer gently, uncovered, stirring occasionally to break up the tomatoes, until the meat is very tender, about 3 hours.
Serve over rice, noodles or polenta.