In a large pot, combine beer, onion, cumin, salt, cayenne pepper and green pepper. Add the water, and bring to a boil. Add the meat, lower heat, cover and braise the meat until it is very soft and tender-about 1 1/2 to 2 hours, depending on thickness.
Drain the meat well, and grill it over a charcoal fire or under a broiler just to heat it and impart a crispy texture.
Recipe courtesy of David Rosengarten