Pour the lemon juice in a bowl. Add half the lemon rind and the remaining ingredients for the marinade. Mix well.
Pour over the meat, cover and marinate in the refrigerator for at least two hours.
Drain the steaks and grill for at least 12 minutes to obtain medium doneness.
Turn the steaks halfway through the cooking time, and season to taste.
Sprinkle with lemon rind and fresh parsley, and serve.