Instructions

1. Mix the vinegar with mint leaves. Finely slice the onion and add to the vinegar mixture.
2. Place the steaks in a shallow dish and pour over the mixture. Make sure they are well covered. Marinate for about 1 hour or so if you can.
3. Oil a griddle pan, then heat it. When hot add the onion slices & steak, using a slotted spoon. Season steaks and fry them on both sides for 3-4 minutes to your liking.
4. Transfer the steaks to a plate, cover and rest.
5. Pour the marinade into the pan, sprinkle with the sugar, then reduce it by half. Pour in the stock and reduce the sauce by half again.
6. Serve the steak with the sauce drizzled over it.