In a 2-quart saucepan combine the stewed tomatoes, water, and hot pepper sauce. Bring to boiling. Stir in rice; return to boiling then reduce heat. Cover and simmer for 20 minutes. Remove from heat; let stand for 5 minutes.
Meanwhile, combine chili powder, salt, cumin, pepper, and cinnamon. Rub spice mixture into flank steak on all sides. Place steak on unheated rack of broiler pan. Broil steak 3 inches from the heat for 6 minutes. Turn and broil to desired doneness (allowing about 7 to 8 minutes more for medium-rare). Or, grill steakdirectly over medium coals for 18 to 22 minutes total for medium doneness, turning once.
To serve, thinly slice flank steak diagonally across the grain. Fluff rice with a fork. Serve steak slices over rice; sprinkle with cilantro or parsley, if desired. Makes 4 to 6 servings.