Barbecued London Broil

1 (1 1/2 or 2 pound) flank steak
1 tablespoon sherry or any dry red wine
1 tablespoon soy sauce
2 tablespoons granulated sugar
1/2 teaspoon salt
1/4 teaspoon cinnamon

Score meat on all sides. Mix together remaining ingredients. Put on meat and let stand 1 1/2 to 2 hours, then place meat in broiler pan about 4 inches from heat. Broil about 10 minutes or a little longer on each side. Ten minutes is for medium rare.

To serve, cut diagonally across the grain into very thin slices.