In a medium size mixing bowl, combine egg and Worcestershire sauce. Stir in rye bread crumbs, mustard, pepper and garlic powder. Add ground beef and mix well. Shape the meat mixture into 12 (1/4" thick) patties.
Place about 2 tablespoons blue cheese atop each of 6 patties. Spread to within 1/2" of edges. Top with remaining patties. Press meat around edges to seal well.
Place patties on a rack in an unheated broiler pan. Broil 3" to 4" from heat about 13 minutes total or until done, turning once. Or, grill patties, on an uncovered grill, directly over medium hot coals for 13 to 14 minutes total or until done, turning once. Serve burgers on toasted buns with alfalfa sprouts. Serves 6.
