Heat lard in skillet. Add meat about 1 lb at a time, removing after each lb. is browned. After all beef is browned, put onions and garlic in pan and cook until soft. Place beef and onions in large pot. Add peppers, tomatillos, tomato paste, beef stock, coriander, cumin, salt and pepper.
Dip tortillas into hot oil for a few seconds to soften.
Fry in hot oil until crisp, turning once. Remove and drain. Slide under broiler to melt cheese. Serve topped with onions and peppers.