In a small bowl or 2-cup measure, blend the mustard, cumin, bay leaf, and garlic. Add the boiling broth and blend well, mashing any lumps of mustard against the sides of the bowl or cup. Stir in the Worcestershire sauce, vinegar, oil and pepper sauce. Cover and let cool. Place the steaks in a plastic bag or shallow dish, add the marinade, turn and let marinate 2 to 3 hours at room temperature, turning 2 or 3 times. Remove the meat from the marinade and grill 4 to 13 cm above hot coals until well browned, 6 to 8 minutes; turn and brown the other side for 6 to 8 minutes. Brush with the marinade and serve at once. NOTE: Any leftover marinade can be frozen and re-used.